Mathematical Olympiad Treasures Problem 3.27 how many ways to fill a table such that product of entries equal -1
71098
number of table with $1$ and $-1$
81042
How can we draw $14$ squares to obtain an $8 \times 8$ table divided into $64$ unit squares?
123690
Olympiad question on Pigeonhole principle
70761
Number of ways to connect sets of $k$ dots in a perfect $n$-gon
97265
count the ways to fill a $4\times n$ board with dominoes
57986
Sum of products of combinatorials
152333
A problem based on pigeonhole
54794
British Olympiad; Combinatorics Recursion
150281
Am I on the right track to figure out this combinatorics problem?
106485
Olympiad Geometry Problem
155372
Find the number of permutations in $S_n$ containing fixed elements in one cycle
141101
Russia (2000) contest:Prove the existence of a pair of rows and columns with intersections differently coloured
42270
Combinatorics - Painting the Unit Squares of a 3x3 Square
1627
Cartesian product of an arbitrary number of sets
97908
Finding the no. of possible matrices given the order and limited no. of entries
78593
Prove that the product of four consecutive positive integers plus one is a perfect square
69833
Number of elements not equal to their inverses is even number