problem_id
stringlengths
12
21
task_type
stringclasses
1 value
prompt
stringlengths
0
13.6k
verification_info
stringlengths
20
1.24k
metadata
stringclasses
89 values
__index_level_0__
int64
0
776k
numina_1.5_212
verifiable_math
II OM - III - Task 1 A beam of length $ a $ has been suspended horizontally by its ends on two parallel ropes of equal length $ b $. We rotate the beam by an angle $ \varphi $ around a vertical axis passing through the center of the beam. By how much will the beam be raised?
{"ground_truth": "\\sqrt{b^2-(\\frac{}"}
{"source": "olympiads", "problem_type": "Geometry"}
200
numina_1.5_213
verifiable_math
LVII OM - III - Problem 2 Determine all positive integers $ k $ for which the number $ 3^k+5^k $ is a power of an integer with an exponent greater than 1.
{"ground_truth": "1"}
{"source": "olympiads", "problem_type": "Number Theory"}
201
numina_1.5_214
verifiable_math
XXIV OM - I - Problem 12 In a class of n students, a Secret Santa event was organized. Each student draws the name of the person for whom they are to buy a gift, so student $ A_1 $ buys a gift for student $ A_2 $, $ A_2 $ buys a gift for $ A_3 $, ..., $ A_k $ buys a gift for $ A_1 $, where $ 1 \leq k \leq n $. Assuming that all drawing outcomes are equally probable, calculate the probability that $ k = n $.
{"ground_truth": "\\frac{1}{n}"}
{"source": "olympiads", "problem_type": "Combinatorics"}
202
numina_1.5_215
verifiable_math
VIII OM - I - Task 6 Find a four-digit number, whose first two digits are the same, the last two digits are the same, and which is a square of an integer.
{"ground_truth": "7744"}
{"source": "olympiads", "problem_type": "Number Theory"}
203
numina_1.5_216
verifiable_math
XXXIV OM - I - Problem 1 $ A $ tosses a coin $ n $ times, $ B $ tosses it $ n+1 $ times. What is the probability that $ B $ will get more heads than $ A $?
{"ground_truth": "\\frac{1}{2}"}
{"source": "olympiads", "problem_type": "Combinatorics"}
204
numina_1.5_219
verifiable_math
LI OM - II - Problem 4 Point $ I $ is the center of the circle inscribed in triangle $ ABC $, where $ AB \neq AC $. Lines $ BI $ and $ CI $ intersect sides $ AC $ and $ AB $ at points $ D $ and $ E $, respectively. Determine all possible measures of angle $ BAC $ for which the equality $ DI = EI $ can hold.
{"ground_truth": "60"}
{"source": "olympiads", "problem_type": "Geometry"}
205
numina_1.5_220
verifiable_math
XXXIV OM - II - Problem 6 For a given number $ n $, let $ p_n $ denote the probability that when a pair of integers $ k, m $ satisfying the conditions $ 0 \leq k \leq m \leq 2^n $ is chosen at random (each pair is equally likely), the number $ \binom{m}{k} $ is even. Calculate $ \lim_{n\to \infty} p_n $.
{"ground_truth": "1"}
{"source": "olympiads", "problem_type": "Combinatorics"}
206
numina_1.5_221
verifiable_math
L OM - I - Problem 8 Given a natural number $ n \geq 2 $ and an $ n $-element set $ S $. Determine the smallest natural number $ k $ for which there exist subsets $ A_1, A_2, \ldots, A_k $ of the set $ S $ with the following property: for any two distinct elements $ a, b \in S $, there exists a number $ j \in \{1, 2, \ldots, k\} $ such that the set $ A_j \cap \{a, b\} $ is a singleton.
{"ground_truth": "[\\log_2(n-1)+1]"}
{"source": "olympiads", "problem_type": "Combinatorics"}
207
numina_1.5_222
verifiable_math
XLVIII OM - II - Problem 3 Given a set of $ n $ points ($ n \geq 2 $), no three of which are collinear. We color all segments with endpoints in this set such that any two segments sharing a common endpoint have different colors. Determine the smallest number of colors for which such a coloring exists.
{"ground_truth": "[n/2]"}
{"source": "olympiads", "problem_type": "Combinatorics"}
208
numina_1.5_223
verifiable_math
LVII OM - III - Problem 6 Determine all pairs of integers $ a $, $ b $, for which there exists a polynomial $ P(x) $ with integer coefficients, such that the product $ (x^2 + ax + b)\cdot P(x) $ is a polynomial of the form where each of the numbers $ c_0,c_1,\dots ,c_{n-1} $ is equal to 1 or -1.
{"ground_truth": "(-2,1),(-1,-1),(-1,1),(0,-1),(0,1),(1,-1),(1,1),(2,1)"}
{"source": "olympiads", "problem_type": "Algebra"}
209
numina_1.5_224
verifiable_math
XXVIII - I - Task 3 Let $ a $ and $ b $ be natural numbers. A rectangle with sides of length $ a $ and $ b $ has been divided by lines parallel to the sides into unit squares. Through the interiors of how many squares does the diagonal of the rectangle pass?
{"ground_truth": "\\gcd(,b)"}
{"source": "olympiads", "problem_type": "Geometry"}
210
numina_1.5_225
verifiable_math
XVI OM - I - Problem 4 The school organized three trips for its 300 students. The same number of students participated in each trip. Each student went on at least one trip, but half of the participants in the first trip, one-third of the participants in the second trip, and one-fourth of the participants in the third trip only went on one trip. How many students went on each trip? How many participants in the first trip also participated in the second, and how many of them also participated in the third trip?
{"ground_truth": "x=120,y=14,z=27,u=53,w=37"}
{"source": "olympiads", "problem_type": "Combinatorics"}
211
numina_1.5_226
verifiable_math
LIV OM - III - Task 3 Determine all polynomials $ W $ with integer coefficients that satisfy the following condition: for every natural number $ n $, the number $ 2^n-1 $ is divisible by $ W(n) $.
{"ground_truth": "W(x)=1orW(x)=-1"}
{"source": "olympiads", "problem_type": "Number Theory"}
212
numina_1.5_227
verifiable_math
VI OM - II - Task 3 What should be the angle at the vertex of an isosceles triangle so that a triangle can be constructed with sides equal to the height, base, and one of the remaining sides of this isosceles triangle?
{"ground_truth": "106"}
{"source": "olympiads", "problem_type": "Geometry"}
213
numina_1.5_229
verifiable_math
XXIX OM - II - Problem 4 From the vertices of a regular $2n$-gon, 3 different points are chosen randomly. Let $p_n$ be the probability that the triangle with vertices at the chosen points is acute. Calculate $\lim_{n\to \infty} p_n$. Note. We assume that all choices of three different points are equally probable.
{"ground_truth": "\\frac{1}{4}"}
{"source": "olympiads", "problem_type": "Combinatorics"}
214
numina_1.5_230
verifiable_math
IX OM - II - Task 2 Six equal disks are placed on a plane in such a way that their centers lie at the vertices of a regular hexagon with a side equal to the diameter of the disks. How many rotations will a seventh disk of the same size make while rolling externally on the same plane along the disks until it returns to its initial position?
{"ground_truth": "4"}
{"source": "olympiads", "problem_type": "Geometry"}
215
numina_1.5_231
verifiable_math
XXXVI OM - III - Problem 1 Determine the largest number $ k $ such that for every natural number $ n $ there are at least $ k $ natural numbers greater than $ n $, less than $ n+17 $, and coprime with the product $ n(n+17) $.
{"ground_truth": "1"}
{"source": "olympiads", "problem_type": "Number Theory"}
216
numina_1.5_232
verifiable_math
LVIII OM - I - Problem 1 Problem 1. Solve in real numbers $ x $, $ y $, $ z $ the system of equations
{"ground_truth": "(x,y,z)=(-2,-2,-2),(\\frac{1}{3},\\frac{1}{3},\\frac{1}{3}),(2,2,-3),(-\\frac{1}{3},-\\frac{1}{3},-\\frac{16}{3}),(2,-3,2),(-\\frac{1}{3}"}
{"source": "olympiads", "problem_type": "Algebra"}
217
numina_1.5_234
verifiable_math
XIII OM - I - Problem 6 Factor the quadratic polynomial into real factors where $ p $ and $ q $ are real numbers satisfying the inequality Please note that the mathematical expressions and symbols are kept as they are, only the text has been translated.
{"ground_truth": "x^4+px^2+(x^2+\\alphax+\\beta)(x^2-\\alphax+\\beta)"}
{"source": "olympiads", "problem_type": "Algebra"}
218
numina_1.5_235
verifiable_math
XXXVIII OM - III - Zadanie 5 Wyznaczyć najmniejszą liczbę naturalną $ n $, dla której liczba $ n^2-n+11 $ jest iloczynem czterech liczb pierwszych (niekoniecznie różnych).
{"ground_truth": "132"}
{"source": "olympiads", "problem_type": "Number Theory"}
219
numina_1.5_236
verifiable_math
XXV OM - III - Task 2 Salmon swimming upstream must overcome two waterfalls. The probability that a salmon will overcome the first waterfall in a given attempt is $ p > 0 $, and the probability of overcoming the second waterfall in a given attempt is $ q > 0 $. We assume that successive attempts to overcome the waterfalls are independent. Calculate the probability of the event that the salmon will not overcome the first waterfall in $ n $ attempts, given that in $ n $ attempts it will not overcome both waterfalls.
{"ground_truth": "\\max(0,1-\\frac{p}{q})"}
{"source": "olympiads", "problem_type": "Algebra"}
220
numina_1.5_237
verifiable_math
LIX OM - I - Task 7 In an $ n $-person association, there are $ 2n-1 $ committees (any non-empty set of association members forms a committee). A chairperson must be selected in each committee. The following condition must be met: If committee $ C $ is the union $ C = A\cup B $ of two committees $ A $ and $ B $, then the chairperson of committee $ C $ is also the chairperson of at least one of the committees $ A $, $ B $. Determine the number of possible selections of chairpersons.
{"ground_truth": "n!"}
{"source": "olympiads", "problem_type": "Combinatorics"}
221
numina_1.5_238
verifiable_math
XVII OM - I - Problem 4 On a plane, a circle and a point $ M $ are given. Find points $ A $ and $ B $ on the circle such that the segment $ AB $ has a given length $ d $, and the angle $ AMB $ is equal to a given angle $ \alpha $.
{"ground_truth": "4,3,2,1,\u62160"}
{"source": "olympiads", "problem_type": "Geometry"}
222
numina_1.5_239
verifiable_math
XXXII - I - Problem 10 Determine all functions $ f $ mapping the set of all rational numbers $ \mathbb{Q} $ to itself that satisfy the following conditions: a) $ f(1)=2 $, b) $ f(xy) = f(x)f(y)-f(x+y)+1 $ for $ x, y \in \mathbb{Q} $.
{"ground_truth": "f(x)=x+1"}
{"source": "olympiads", "problem_type": "Algebra"}
223
numina_1.5_240
verifiable_math
XXXI - III - Task 1 Calculate the area of an octagon inscribed in a circle, knowing that each of four consecutive sides of this octagon has a length of 1, and each of the remaining four has a length of 2.
{"ground_truth": "6+4\\sqrt{2}-1"}
{"source": "olympiads", "problem_type": "Geometry"}
224
numina_1.5_241
verifiable_math
XII OM - II - Task 4 Find the last four digits of the number $ 5^{5555} $.
{"ground_truth": "8125"}
{"source": "olympiads", "problem_type": "Number Theory"}
225
numina_1.5_242
verifiable_math
XLVII OM - III - Problem 1 Determine all pairs $ (n,r) $, where $ n $ is a positive integer and $ r $ is a real number, for which the polynomial $ (x + 1)^n - r $ is divisible by the polynomial $ 2x^2 + 2x + 1 $.
{"ground_truth": "(4k,(-\\frac{1}{4})^k)"}
{"source": "olympiads", "problem_type": "Algebra"}
226
numina_1.5_244
verifiable_math
XXXVIII OM - II - Zadanie 4 Wyznaczyć wszystkie pary liczb rzeczywistych $ a, b $, dla których wielomiany $ x^4 + 2ax^2 + 4bx + a^2 $ i $ x^3 + ax - b $ mają dwa różne wspólne pierwiastki rzeczywiste.
{"ground_truth": "(,0),where0"}
{"source": "olympiads", "problem_type": "Algebra"}
227
numina_1.5_245
verifiable_math
VI OM - II - Task 1 Calculate the sum $ x^4 + y^4 + z^4 $ given that $ x + y + z = 0 $ and $ x^2 + y^2 + z^2 = a $, where $ a $ is a given positive number.
{"ground_truth": "\\frac{^2}{2}"}
{"source": "olympiads", "problem_type": "Algebra"}
228
numina_1.5_248
verifiable_math
XXI OM - III - Task 5 In how many ways can a set consisting of twelve elements be divided into six disjoint two-element sets?
{"ground_truth": "11\\cdot9\\cdot7\\cdot5\\cdot3"}
{"source": "olympiads", "problem_type": "Combinatorics"}
229
numina_1.5_249
verifiable_math
XXII OM - II - Problem 1 In how many ways can $ k $ fields of a chessboard $ n \times n $ ($ k \leq n $) be chosen so that no two of the selected fields lie in the same row or column?
{"ground_truth": "\\binom{n}{k}n(n-1)\\ldots(n-k+1)"}
{"source": "olympiads", "problem_type": "Combinatorics"}
230
numina_1.5_250
verifiable_math
XXXIII OM - III - Problem 1 Indicate such a way of arranging $ n $ girls and $ n $ boys around a round table so that the number $ d_n - c_n $ is maximized, where $ d_n $ is the number of girls sitting between two boys, and $ c_n $ is the number of boys sitting between two girls.
{"ground_truth": "[\\frac{n}{2}]-1"}
{"source": "olympiads", "problem_type": "Combinatorics"}
231
numina_1.5_251
verifiable_math
III OM - I - Task 4 a) Given points $ A $, $ B $, $ C $ not lying on a straight line. Determine three mutually parallel lines passing through points $ A $, $ B $, $ C $, respectively, so that the distances between adjacent parallel lines are equal. b) Given points $ A $, $ B $, $ C $, $ D $ not lying on a plane. Determine four mutually parallel planes passing through points $ A $, $ B $, $ C $, $ D $, respectively, so that the distances between adjacent parallel planes are equal.
{"ground_truth": "12"}
{"source": "olympiads", "problem_type": "Geometry"}
232
numina_1.5_252
verifiable_math
LX OM - I - Task 1 On some fields of a chessboard of size $ m \times n $, rooks are placed. It is known that any rook is in the attack range of at most two other rooks. Determine, depending on $ m, n \geq 2 $, the maximum number of rooks on the chessboard, for which such a situation is possible.
{"ground_truth": "+n"}
{"source": "olympiads", "problem_type": "Combinatorics"}
233
numina_1.5_253
verifiable_math
LX OM - II - Task 5 Determine all integers $ n \geqslant 4 $ with the following property: Among any $ n $ different 3-element subsets of an $ n $-element set, one can select two subsets that have exactly one element in common.
{"ground_truth": "n\\geq4"}
{"source": "olympiads", "problem_type": "Combinatorics"}
234
numina_1.5_254
verifiable_math
XXIII OM - I - Problem 6 Determine for which digits $ a $ the decimal representation of a number $ \frac{n(n+1)}{2} $ ($ n\in \mathbb{N} $) consists entirely of the digit $ a $.
{"ground_truth": "5,6"}
{"source": "olympiads", "problem_type": "Number Theory"}
235
numina_1.5_255
verifiable_math
XXVI - I - Problem 11 A ship is moving at a constant speed along a straight line with an east-west direction. Every $ T $ minutes, the direction of movement is randomly chosen: with probability $ p $, the ship moves in the eastern direction for the next $ T $ minutes, and with probability $ q= 1-p $, it moves in the western direction. At a point outside the line, there is a submarine whose task is to torpedo the ship. The travel time of the torpedo from the point of firing to any point on the ship's track is $ 2T $. The captain of the submarine knows the value of $ p $ and aims to maximize the probability of hitting the ship. How should $ p $ be chosen to minimize the probability of the ship being torpedoed?
{"ground_truth": "\\frac{4}{9}"}
{"source": "olympiads", "problem_type": "Combinatorics"}
236
numina_1.5_256
verifiable_math
LI OM - I - Task 5 Determine all pairs $ (a,b) $ of natural numbers for which the numbers $ a^3 + 6ab + 1 $ and $ b^3 + 6ab + 1 $ are cubes of natural numbers.
{"ground_truth": "(1,1)"}
{"source": "olympiads", "problem_type": "Number Theory"}
237
numina_1.5_257
verifiable_math
XXXV OM - I - Problem 9 Three events satisfy the conditions: a) their probabilities are equal, b) any two of them are independent, c) they do not occur simultaneously. Determine the maximum value of the probability of each of these events.
{"ground_truth": "\\frac{1}{2}"}
{"source": "olympiads", "problem_type": "Combinatorics"}
238
numina_1.5_258
verifiable_math
VII OM - I - Task 3 In a square $ABCD$ with area $S$, vertex $A$ is connected to the midpoint of side $BG$, vertex $B$ is connected to the midpoint of side $CD$, vertex $C$ is connected to the midpoint of side $DA$, and vertex $D$ is connected to the midpoint of side $AB$. Calculate the area of the part of the square that contains its center.
{"ground_truth": "\\frac"}
{"source": "olympiads", "problem_type": "Geometry"}
239
numina_1.5_259
verifiable_math
XLVIII OM - III - Problem 2 Find all triples of real numbers $ x $, $ y $, $ z $ satisfying the system of equations
{"ground_truth": "(x,y,z)=(\\1/3,\\1/3,\\1/3)(x,y,z)=(\\1/\\sqrt{3},0,0),(0,\\1/\\sqrt{3},0),(0,0,\\1/\\sqrt{3})"}
{"source": "olympiads", "problem_type": "Algebra"}
240
numina_1.5_260
verifiable_math
L OM - I - Task 3 In an isosceles triangle $ ABC $, angle $ BAC $ is a right angle. Point $ D $ lies on side $ BC $, such that $ BD = 2 \cdot CD $. Point $ E $ is the orthogonal projection of point $ B $ onto line $ AD $. Determine the measure of angle $ CED $.
{"ground_truth": "45"}
{"source": "olympiads", "problem_type": "Geometry"}
241
numina_1.5_263
verifiable_math
XXX OM - I - Task 8 Among the cones inscribed in the sphere $ B $, the cone $ S_1 $ was chosen such that the sphere $ K_1 $ inscribed in the cone $ S_1 $ has the maximum volume. Then, a cone $ S_2 $ of maximum volume was inscribed in the sphere $ B $, and a sphere $ K_2 $ was inscribed in the cone $ S_2 $. Determine which is greater: the sum of the volumes of $ S_1 $ and $ K_1 $, or the sum of the volumes of $ S_2 $ and $ K_2 $.
{"ground_truth": "V(\\frac{\\sqrt{3}}{3})>V(\\frac{1}{2})"}
{"source": "olympiads", "problem_type": "Geometry"}
242
numina_1.5_264
verifiable_math
XXXI - I - Task 1 Determine for which values of the parameter $ a $ a rhombus with side length $ a $ is a cross-section of a cube with edge length 2 by a plane passing through the center of the cube.
{"ground_truth": "[2,\\sqrt{5}]"}
{"source": "olympiads", "problem_type": "Geometry"}
243
numina_1.5_265
verifiable_math
VIII OM - I - Zadanie 5 Jaki warunek powinna spełniać liczbą $ q $, aby istniał trójkąt, którego boki tworzą postęp geometryczny o ilorazie $ q $?
{"ground_truth": "\\frac{-1+\\sqrt{5}}{2}<\\frac{1+\\sqrt{5}}{2}"}
{"source": "olympiads", "problem_type": "Number Theory"}
244
numina_1.5_266
verifiable_math
LV OM - I - Task 7 Find all solutions to the equation $ a^2+b^2=c^2 $ in positive integers such that the numbers $ a $ and $ c $ are prime, and the number $ b $ is the product of at most four prime numbers.
{"ground_truth": "(3,4,5),(5,12,13),(11,60,61)"}
{"source": "olympiads", "problem_type": "Number Theory"}
245
numina_1.5_267
verifiable_math
LX OM - III - Zadanie 2 Let $ S $ be the set of all points in the plane with both coordinates being integers. Find the smallest positive integer $ k $ for which there exists a 60-element subset of the set $ S $ with the following property: For any two distinct elements $ A $ and $ B $ of this subset, there exists a point $ C \in S $ such that the area of triangle $ ABC $ is equal to $ k $.
{"ground_truth": "210"}
{"source": "olympiads", "problem_type": "Geometry"}
246
numina_1.5_268
verifiable_math
I OM - B - Task 1 Determine the coefficients $ a $ and $ b $ of the equation $ x^2 + ax + b=0 $ such that the values of $ a $ and $ b $ themselves are roots of this equation.
{"ground_truth": "1,0"}
{"source": "olympiads", "problem_type": "Algebra"}
247
numina_1.5_269
verifiable_math
I OM - B - Zadanie 1 Wyznaczyć współczynniki $ a $ i $ b $, równania $ x^2 + ax +b=0 $ tak, aby same wartości $ a $ i $ b $ były pierwiastkami tego równania.
{"ground_truth": "0,0\u62161,-2"}
{"source": "olympiads", "problem_type": "Algebra"}
248
numina_1.5_270
verifiable_math
XXI OM - II - Problem 6 If $ A $ is a subset of set $ X $, then we define $ A^1 = A $, $ A^{-1} = X - A $. Subsets $ A_1, A_2, \ldots, A_k $ are called mutually independent if the product $ A_1^{\varepsilon_1} \cap A_2^{\varepsilon_2} \ldots A_k^{\varepsilon_k} $ is non-empty for every system of numbers $ \varepsilon_1, \varepsilon_2, \ldots, \varepsilon_k $, such that $ |\varepsilon_i| = 1 $ for $ i = 1, 2, \ldots, k $. What is the maximum number of mutually independent subsets of a $ 2^n $-element set?
{"ground_truth": "n"}
{"source": "olympiads", "problem_type": "Combinatorics"}
249
numina_1.5_271
verifiable_math
X OM - III - Task 3 Given is a pyramid with a square base $ABCD$ and apex $S$. Find the shortest path that starts and ends at point $S$ and passes through all the vertices of the base.
{"ground_truth": "k++3a"}
{"source": "olympiads", "problem_type": "Geometry"}
250
numina_1.5_272
verifiable_math
XIX OM - I - Problem 4 In the plane, given are parallel lines $ a $ and $ b $ and a point $ M $ lying outside the strip bounded by these lines. Determine points $ A $ and $ B $ on lines $ a $ and $ b $, respectively, such that segment $ AB $ is perpendicular to $ a $ and $ b $, and the angle $ AMB $ is the largest.
{"ground_truth": "ABlieonthecirclewithdiameterMN"}
{"source": "olympiads", "problem_type": "Geometry"}
251
numina_1.5_273
verifiable_math
XIII OM - III - Task 4 In how many ways can a set of $ n $ items be divided into two sets?
{"ground_truth": "2^{n-1}-1"}
{"source": "olympiads", "problem_type": "Combinatorics"}
252
numina_1.5_274
verifiable_math
LV OM - III - Task 5 Determine the maximum number of lines in space passing through a fixed point and such that any two intersect at the same angle.
{"ground_truth": "6"}
{"source": "olympiads", "problem_type": "Geometry"}
253
numina_1.5_278
verifiable_math
XVI OM - III - Task 5 Points $ A_1 $, $ B_1 $, $ C_1 $ divide the sides $ BC $, $ CA $, $ AB $ of triangle $ ABC $ in the ratios $ k_1 $, $ k_2 $, $ k_3 $. Calculate the ratio of the areas of triangles $ A_1B_1C_1 $ and $ ABC $.
{"ground_truth": "\\frac{k_1k_2k_3}{(1+k_1)(1+k_2)(1+k_3)}"}
{"source": "olympiads", "problem_type": "Geometry"}
254
numina_1.5_279
verifiable_math
LVII OM - I - Problem 1 Determine all non-negative integers $ n $ for which the number $ 2^n +105 $ is a perfect square of an integer.
{"ground_truth": "4,6,8"}
{"source": "olympiads", "problem_type": "Number Theory"}
255
numina_1.5_280
verifiable_math
XVI OM - II - Task 4 Find all prime numbers $ p $ such that $ 4p^2 +1 $ and $ 6p^2 + 1 $ are also prime numbers.
{"ground_truth": "5"}
{"source": "olympiads", "problem_type": "Number Theory"}
256
numina_1.5_281
verifiable_math
XXXVIII OM - II - Problem 5 Determine all prime numbers $ p $ and natural numbers $ x, y $, for which $ p^x - y^3 = 1 $.
{"ground_truth": "(2,1,1)(3,2,2)"}
{"source": "olympiads", "problem_type": "Number Theory"}
257
numina_1.5_282
verifiable_math
XXVI - I - Problem 5 Determine all integers $ m $ for which the polynomial $ x^3-mx^2+mx-(m^2+1) $ has an integer root.
{"ground_truth": "=0=-3"}
{"source": "olympiads", "problem_type": "Algebra"}
258
numina_1.5_283
verifiable_math
XL OM - I - Task 6 Calculate the sum of the series $ \sum_{n\in A}\frac{1}{2^n} $, where the summation runs over the set $ A $ of all natural numbers not divisible by 2, 3, 5.
{"ground_truth": "\\frac{1}{1-2^{-30}}(\\frac{1}{2^1}+\\frac{1}{2^7}+\\frac{1}{2^{11}}+\\frac{1}{2^{13}}+\\frac{1}{2^{17}}+\\frac{1}{2^{19}}+\\frac{1}{2^{23}}+\\frac{1}{2^{}"}
{"source": "olympiads", "problem_type": "Number Theory"}
259
numina_1.5_284
verifiable_math
III OM - III - Task 6 In a round tower with an internal diameter of $2$ m, there are spiral stairs with a height of $6$ m. The height of each step is $0.15$ m. In a horizontal projection, the steps form adjacent circular sectors with an angle of $18^\circ$. The narrower ends of the steps are attached to a round pillar with a diameter of $0.64$ m, whose axis coincides with the axis of the tower. Calculate the maximum length of a straight rod that can be moved up these stairs from the bottom to the top (do not take into account the thickness of the rod or the thickness of the plates from which the stairs are made).
{"ground_truth": "4.47\\textrm{}"}
{"source": "olympiads", "problem_type": "Geometry"}
260
numina_1.5_285
verifiable_math
XXXIX OM - II - Problem 3 Inside an acute triangle $ ABC $, consider a point $ P $ and its projections $ L, M, N $ onto the sides $ BC, CA, AB $, respectively. Determine the point $ P $ for which the sum $ |BL|^2 + |CM|^2 + |AN|^2 $ is minimized.
{"ground_truth": "PisthecircumcenteroftriangleABC"}
{"source": "olympiads", "problem_type": "Geometry"}
261
numina_1.5_286
verifiable_math
XXXVI OM - I - Zadanie 9 W urnie jest 1985 kartek z napisanymi liczbami 1,2,3,..., 1985, każda lczba na innej kartce. Losujemy bez zwracania 100 kartek. Znaleźć wartość oczekiwaną sumy liczb napisanych na wylosowanych kartkach.
{"ground_truth": "99300"}
{"source": "olympiads", "problem_type": "Combinatorics"}
262
numina_1.5_287
verifiable_math
LII OM - I - Task 4 Determine whether 65 balls with a diameter of 1 can fit into a cubic box with an edge of 4.
{"ground_truth": "66"}
{"source": "olympiads", "problem_type": "Geometry"}
263
numina_1.5_288
verifiable_math
II OM - III - Task 2 What digits should be placed instead of zeros in the third and fifth positions in the number $ 3000003 $ to obtain a number divisible by $ 13 $?
{"ground_truth": "3080103,3040203,3020303,3090503,3060603,3030703,3000803"}
{"source": "olympiads", "problem_type": "Number Theory"}
264
numina_1.5_289
verifiable_math
L OM - I - Task 5 Find all pairs of positive integers $ x $, $ y $ satisfying the equation $ y^x = x^{50} $.
{"ground_truth": "8"}
{"source": "olympiads", "problem_type": "Number Theory"}
265
numina_1.5_290
verifiable_math
VIII OM - I - Problem 8 In the rectangular prism $ ABCDA_1B_1C_1D_1 $, the lengths of the edges are given as $ AA_1 = a $, $ AB = b $, $ AD = c $. On the face $ A_1B_1C_1D_1 $, a point $ M $ is chosen at a distance $ p $ from the side $ A_1B_1 $, and at a distance $ q $ from the side $ A_1D_1 $, and a parallelepiped is constructed with the base $ ABCD $ and the lateral edge $ AM $. Calculate the area of the lateral faces of this parallelepiped.
{"ground_truth": "\\sqrt{^2+}"}
{"source": "olympiads", "problem_type": "Geometry"}
266
numina_1.5_292
verifiable_math
XIII OM - I - Problem 2 How many digits do all natural numbers with at most $ m $ digits have in total?
{"ground_truth": "9\\cdot\\frac{10^-1}{9}\\cdot\\frac{(+1)}{2}"}
{"source": "olympiads", "problem_type": "Combinatorics"}
267
numina_1.5_294
verifiable_math
XV OM - I - Problem 8 On three pairwise skew edges of a cube, choose one point on each in such a way that the sum of the squares of the sides of the triangle formed by them is minimized.
{"ground_truth": "\\frac{9}{2}^2"}
{"source": "olympiads", "problem_type": "Geometry"}
268
numina_1.5_295
verifiable_math
XLVII OM - I - Problem 1 Determine all integers $ n $ for which the equation $ 2 \sin nx = \tan x + \cot x $ has solutions in real numbers $ x $.
{"ground_truth": "8k+2"}
{"source": "olympiads", "problem_type": "Algebra"}
269
numina_1.5_296
verifiable_math
XLII OM - I - Problem 5 Given a segment $ AD $. Find points $ B $ and $ C $ on it, such that the product of the lengths of the segments $ AB $, $ AC $, $ AD $, $ BC $, $ BD $, $ CD $ is maximized.
{"ground_truth": "\\frac{1}{5}\\sqrt{5}"}
{"source": "olympiads", "problem_type": "Geometry"}
270
numina_1.5_297
verifiable_math
LX OM - I - Task 12 Given a prime number $ p $. On the left side of the board, the numbers $ 1, 2, 3, \cdots, p - 1 $ are written, while on the right side, the number $ 0 $ is written. We perform a sequence of $ p - 1 $ moves, each of which proceeds as follows: We select one of the numbers written on the left side of the board, add it to all the remaining numbers on the board, and then erase the selected number. Determine for which values of $ p $ it is possible to choose the numbers in such a way that the number remaining on the board after all moves have been performed is divisible by $ p $.
{"ground_truth": "Forallpexcept23"}
{"source": "olympiads", "problem_type": "Number Theory"}
271
numina_1.5_300
verifiable_math
XXX OM - I - Task 12 To qualify for the team, a player must pass at least four out of seven tests with a positive result. If the player prepares for all tests, the probability of success in each of these tests is the same and equals $ \frac{1}{2} $. If the player prepares for five tests, the corresponding probability of success in each of these five tests will be $ \frac{3}{4} $. If, however, the player prepares for four tests, the probability of success in each of these four tests will be $ \frac{4}{5} $. Which of the three mentioned ways of preparing is the most advantageous for the player?
{"ground_truth": "\\frac{81}{128}"}
{"source": "olympiads", "problem_type": "Combinatorics"}
272
numina_1.5_301
verifiable_math
XXXIX OM - I - Problem 1 For each positive number $ a $, determine the number of roots of the polynomial $ x^3+(a+2)x^2-x-3a $.
{"ground_truth": "3"}
{"source": "olympiads", "problem_type": "Algebra"}
273
numina_1.5_302
verifiable_math
XLVIII OM - II - Problem 4 Determine all triples of positive integers having the following property: the product of any two of them gives a remainder of $ 1 $ when divided by the third number.
{"ground_truth": "(5,3,2)"}
{"source": "olympiads", "problem_type": "Number Theory"}
274
numina_1.5_303
verifiable_math
LVIII OM - I - Problem 2 Determine all pairs of positive integers $ k $, $ m $, for which each of the numbers $ {k^2+4m} $, $ {m^2+5k} $ is a perfect square.
{"ground_truth": "(1,2),(9,22),(8,9)"}
{"source": "olympiads", "problem_type": "Number Theory"}
275
numina_1.5_305
verifiable_math
XX OM - II - Task 2 Find all four-digit numbers in which the thousands digit is equal to the hundreds digit, and the tens digit is equal to the units digit, and which are squares of integers.
{"ground_truth": "7744"}
{"source": "olympiads", "problem_type": "Number Theory"}
276
numina_1.5_306
verifiable_math
XXXVIII OM - III - Problem 6 A plane is covered with a grid of regular hexagons with a side length of 1. A path on the grid is defined as a sequence of sides of the hexagons in the grid, such that any two consecutive sides have a common endpoint. A path on the grid is called the shortest if its endpoints cannot be connected by a shorter path. Find the number of shortest paths on the grid with a fixed starting point and a length of 60.
{"ground_truth": "6\\cdot2^{30}-6"}
{"source": "olympiads", "problem_type": "Combinatorics"}
277
numina_1.5_307
verifiable_math
XXXV OM - II - Problem 1 For a given natural number $ n $, find the number of solutions to the equation $ \sqrt{x} + \sqrt{y} = n $ in natural numbers $ x, y $.
{"ground_truth": "n-1"}
{"source": "olympiads", "problem_type": "Number Theory"}
278
numina_1.5_308
verifiable_math
V OM - I - Task 2 Investigate when the sum of the cubes of three consecutive natural numbers is divisible by $18$.
{"ground_truth": "3"}
{"source": "olympiads", "problem_type": "Number Theory"}
279
numina_1.5_310
verifiable_math
XLVI OM - III - Problem 5 Let $ n $ and $ k $ be natural numbers. From an urn containing 11 slips numbered from 1 to $ n $, we draw slips one by one, without replacement. When a slip with a number divisible by $ k $ appears, we stop drawing. For a fixed $ n $, determine those numbers $ k \leq n $ for which the expected value of the number of slips drawn is exactly $ k $.
{"ground_truth": "k"}
{"source": "olympiads", "problem_type": "Combinatorics"}
280
numina_1.5_311
verifiable_math
LIV OM - I - Task 7 At Aunt Reni's, $ n \geq 4 $ people met (including Aunt Reni). Each of the attendees gave at least one gift to at least one of the others. It turned out that everyone gave three times as many gifts as they received, with one exception: Aunt Reni gave only $ \frac{1}{6} $ of the number of gifts she received. Determine, depending on $ n $, the smallest possible number of gifts Aunt Reni could have received.
{"ground_truth": "12[(n+3)/5]"}
{"source": "olympiads", "problem_type": "Combinatorics"}
281
numina_1.5_312
verifiable_math
XXXV OM - III - Problem 1 Determine the number of functions $ f $ mapping an $ n $-element set to itself such that $ f^{n-1} $ is a constant function, while $ f^{n-2} $ is not a constant function, where $ f^k = f\circ f \circ \ldots \circ f $, and $ n $ is a fixed natural number greater than 2.
{"ground_truth": "n!"}
{"source": "olympiads", "problem_type": "Combinatorics"}
282
numina_1.5_314
verifiable_math
XXI OM - I - Problem 12 Find the smallest positive number $ r $ with the property that in a regular tetrahedron with edge length 1, there exist four points such that the distance from any point of the tetrahedron to one of them is $ \leq r $.
{"ground_truth": "\\frac{\\sqrt{6}}{8}"}
{"source": "olympiads", "problem_type": "Geometry"}
283
numina_1.5_315
verifiable_math
LVI OM - I - Task 2 Determine all natural numbers $ n>1 $ for which the value of the sum $ 2^{2}+3^{2}+\ldots+n^{2} $ is a power of a prime number with a natural exponent.
{"ground_truth": "2,3,4,7"}
{"source": "olympiads", "problem_type": "Number Theory"}
284
numina_1.5_316
verifiable_math
XL OM - II - Task 3 Given is a trihedral angle $ OABC $ with vertex $ O $ and a point $ P $ inside it. Let $ V $ be the volume of the parallelepiped with two vertices at points $ O $ and $ P $, whose three edges are contained in the rays $ OA^{\rightarrow} $, $ OB^{\rightarrow} $, $ OC^{\rightarrow} $. Calculate the minimum volume of the tetrahedron, whose three faces are contained in the faces of the trihedral angle $ OABC $, and the fourth face contains the point $ P $.
{"ground_truth": "\\frac{9}{2}V"}
{"source": "olympiads", "problem_type": "Geometry"}
285
numina_1.5_318
verifiable_math
XLVIII OM - I - Problem 7 Calculate the upper limit of the volume of tetrahedra contained within a sphere of a given radius $ R $, one of whose edges is the diameter of the sphere.
{"ground_truth": "\\frac{1}{3}R^3"}
{"source": "olympiads", "problem_type": "Geometry"}
286
numina_1.5_319
verifiable_math
XXI OM - I - Problem 10 Find the largest natural number $ k $ with the following property: there exist $ k $ different subsets of an $ n $-element set, such that any two of them have a non-empty intersection.
{"ground_truth": "2^{n-1}"}
{"source": "olympiads", "problem_type": "Combinatorics"}
287
numina_1.5_320
verifiable_math
LIX OM - II - Task 1 Determine the maximum possible length of a sequence of consecutive integers, each of which can be expressed in the form $ x^3 + 2y^2 $ for some integers $ x, y $.
{"ground_truth": "5"}
{"source": "olympiads", "problem_type": "Number Theory"}
288
numina_1.5_321
verifiable_math
XV OM - I - Problem 11 In triangle $ ABC $, angle $ A $ is $ 20^\circ $, $ AB = AC $. On sides $ AB $ and $ AC $, points $ D $ and $ E $ are chosen such that $ \measuredangle DCB = 60^\circ $ and $ \measuredangle EBC = 50^\circ $. Calculate the angle $ EDC $.
{"ground_truth": "30"}
{"source": "olympiads", "problem_type": "Geometry"}
289
numina_1.5_322
verifiable_math
XLVI OM - II - Problem 6 A square with side length $ n $ is divided into $ n^2 $ unit squares. Determine all natural numbers $ n $ for which such a square can be cut along the lines of this division into squares, each of which has a side length of 2 or 3.
{"ground_truth": "nisdivisible2or3"}
{"source": "olympiads", "problem_type": "Combinatorics"}
290
numina_1.5_323
verifiable_math
XXVI - III - Task 2 On the surface of a regular tetrahedron with edge length 1, a finite set of segments is chosen in such a way that any two vertices of the tetrahedron can be connected by a broken line composed of some of these segments. Can this set of segments be chosen so that their total length is less than $1 + \sqrt{3}$?
{"ground_truth": "\\sqrt{7}"}
{"source": "olympiads", "problem_type": "Geometry"}
291
numina_1.5_324
verifiable_math
XVI OM - I - Problem 7 On the side $ AB $ of triangle $ ABC $, a point $ K $ is chosen, and points $ M $ and $ N $ are determined on the lines $ AC $ and $ BC $ such that $ KM \perp AC $, $ KN \perp BC $. For what position of point $ K $ is the area of triangle $ MKN $ the largest?
{"ground_truth": "KisthemidpointofsideAB"}
{"source": "olympiads", "problem_type": "Geometry"}
292
numina_1.5_327
verifiable_math
XVII OM - I - Problem 1 Present the polynomial $ x^5 + x + 1 $ as a product of two polynomials of lower degree with integer coefficients.
{"ground_truth": "x^5+x+1=(x^2+x+1)(x^3-x^2+1)"}
{"source": "olympiads", "problem_type": "Algebra"}
293
numina_1.5_328
verifiable_math
XLVI OM - III - Zadanie 3 Dana jest liczba pierwsza $ p \geq 3 $. Określamy ciąg $ (a_n) $ wzorami Wyznaczyć resztę z dzielenia liczby $ a_{p^3} $ przez $ p $.
{"ground_truth": "p-1"}
{"source": "olympiads", "problem_type": "Number Theory"}
294
numina_1.5_329
verifiable_math
XXVIII - II - Task 3 In a hat, there are 7 slips of paper. On the $ n $-th slip, the number $ 2^n-1 $ is written ($ n = 1, 2, \ldots, 7 $). We draw slips randomly until the sum exceeds 124. What is the most likely value of this sum?
{"ground_truth": "127"}
{"source": "olympiads", "problem_type": "Number Theory"}
295
numina_1.5_330
verifiable_math
I OM - B - Task 12 How many sides does a polygon have if each of its angles is $ k $ times larger than the adjacent angle? What values can $ k $ take?
{"ground_truth": "\\frac{1}{2},1,\\frac{3}{2},2,\\dots"}
{"source": "olympiads", "problem_type": "Geometry"}
296
numina_1.5_331
verifiable_math
IV OM - III - Task 3 Through each vertex of a tetrahedron of a given volume $ V $, a plane parallel to the opposite face of the tetrahedron has been drawn. Calculate the volume of the tetrahedron formed by these planes.
{"ground_truth": "27V"}
{"source": "olympiads", "problem_type": "Geometry"}
297
numina_1.5_332
verifiable_math
XLII OM - I - Problem 8 Determine the largest natural number $ n $ for which there exist in space $ n+1 $ polyhedra $ W_0, W_1, \ldots, W_n $ with the following properties: (1) $ W_0 $ is a convex polyhedron with a center of symmetry, (2) each of the polyhedra $ W_i $ ($ i = 1,\ldots, n $) is obtained from $ W_0 $ by a translation, (3) each of the polyhedra $ W_i $ ($ i = 1,\ldots, n $) has a point in common with $ W_0 $, (4) the polyhedra $ W_0, W_1, \ldots, W_n $ have pairwise disjoint interiors.
{"ground_truth": "26"}
{"source": "olympiads", "problem_type": "Geometry"}
298
numina_1.5_333
verifiable_math
XI OM - I - Task 3 Each side of a triangle with a given area $ S $ is divided into three equal parts, and the points of division are connected by segments, skipping one point to form two triangles. Calculate the area of the hexagon that is the common part of these triangles.
{"ground_truth": "\\frac{2}{9}S"}
{"source": "olympiads", "problem_type": "Geometry"}
299