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?
Find positive integers \(x,y,z\) such that \(28x+30y+31z = 365\).
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?
Prove that \(3\) always divides \(2^{2n}-1\), where \(n\) is a positive integer.
Determine all integer solutions to the equation \(24a + 16b = 6\).
John’s father is 28 years older than John and next year he will be exactly three times the age of John. How old is John’s father?
You have an hourglass that measures 8 minutes and an hourglass that measures 12 minutes. How can you measure exactly 44 minutes with them?
Joe has two kinds of weights: 15 grams and 50 grams. He has an infinite supply of each type. Can you help him find a combination that is exactly 310 grams?