You have a jar with 60 jelly beans. you know that 1/3 of the jelly beans are yellow, 1/4 of them are white and the rest is red. you are not allowed to look. how many beans do you have to take out to be absolutely sure to get at least one yellow one?
41 beans¿ If you divide 60 by 1/3 you get 20, so there has to be 40 other beans of either white and red. If you take out 41 you're definitely going to get a yellow.
