Suppose a jar contains 17 red marbles and 31 blue marbles. If you reach in the jar and pull out 2 marbles at random at the same time, find the probability that both are red.

Question

Suppose a jar contains 17 red marbles and 31 blue marbles. If you reach in the jar and pull out 2 marbles at random at the same time, find the probability that both are red.

Answer 1

A tree diagram would help you figure out your probabilities:

The probability of both being red (top path of tree) is 17/48 •16/47 = 272/2256 = 17/141