A square is given, and a quadratic trinomial with a positive leading coefficient is placed in each of its cells. There are coefficents in total, and these coefficents are chosen from the set , and each coefficient is different from each other. Prove that there exists at least one column such that the sum of the six trinomials in that column has a real root.
Product of consecutive terms divisible by a prime number
BR1F1SZ1
N17 minutes ago
by IndoMathXdZ
Source: 2025 Francophone MO Seniors P4
Determine all sequences of strictly positive integers satisfying the following two conditions:
[list]
[*]There exists an integer such that, for all indices ,.
[*]For any prime number and for any index , the number is a multiple of .
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Let be a triangle and let denote the circumcircle of . The foot of altitude from to is . The foot of altitudes from to and are , respectively. Let intersect at , and let intersect at . Prove that is the incenter of triangle
Pairwise distinct points , which lie on a circle, are marked by distinct reals . Let be good for a on the circle different than , if and only if is the greatest number on at least one of the two arcs . Let the score of be the number of good points on the circle. Determine the greatest such that regardless of the values of , there exists a point with score at least .
Aslı tries to make the amount of stones at every unit square is equal
AlperenINAN0
an hour ago
Source: Turkey JBMO TST 2025 P2
Let be a positive integer. Aslı and Zehra are playing a game on an grid. Initially, stones are placed on some of the unit squares of this grid.
On each move (starting with Aslı), Aslı chooses a row or a column that contains at least two squares with different numbers of stones, and Zehra redistributes the stones in that row or column so that after redistribution, the difference in the number of stones between any two squares in that row or column is at most one. Furthermore, this move must change the number of stones in at least one square.
For which values of , regardless of the initial placement of the stones, can Aslı guarantee that every square ends up with the same number of stones?