A box has 7 white balls,9 red balls and 5 green balls, At least how many balls would you have to take in order to ensure that you have 3 balls of same colour?

Guest Mar 10, 2020

#1**+4 **

This known as the "pigeonhole principle"

By taking 7 + 5 + 3 = 15 balls you are guaranteed to end up with 3 red balls......

CPhill Mar 10, 2020