Problems

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Show that if \(1+3+5+7+...+97+99=50^2\), then \(1+3+5+7+...+97+99+101=51^2\). Don’t forget that \((a+b)^2=a^2+2ab+b^2\).

Prove that for all positive integers \(n\) there exists a partition of the set of positive integers \(k\le2^{n+1}\) into sets \(A\) and \(B\) such that \[\sum_{x\in A}x^i=\sum_{x\in B}x^i\] for all integers \(0\le i\le n\).

McDonald’s used to sell Chicken McNuggets in boxes of 6, 9 or 20 in the UK before they introduced the Happy Meal. What is the largest number of Chicken McNuggets that could not be bought? For example, you wouldn’t have been able to buy 8 Chicken McNuggets, but you could have bought \(21 = 6+6+9\) Chicken McNuggets.

Show that the equation \(x^4+y^4=z^4\) cannot satisfied by integers \(x,y,z\) if none of them are 0.

A regular polygon has integer side lengths and its perimeter is 60. How many sides can it have?

Given a piece of paper, we are allowed to cut it into 8 or 12 pieces. Can we get exactly 60 pieces of paper starting with a single piece?

In Pascal’s triangle, what are the numbers in the diagonal next to the diagonal of ones?