If you fail, never give up because FAIL means 'First Attempt In Learning'.— A. P. J. Abdul Kalam

Pigeonhole Principle — quick quiz

5 real IOQM questions on Pigeonhole Principle. Instant scoring and solutions, no signup — see where you stand in ~3 minutes.

Question 1 of 2

HARD

From the set {1, 2, 3, ..., 20}, what is the minimum number of integers that must be chosen to guarantee that at least two chosen integers differ by exactly 5?