Question

A box contains 4 red, 5 green, and 6 blue balls. You take two balls at random without replacement. Find the probability that both balls are red.

Answer 1

Total balls = 6+4+5 = 15
Red balls = 4
First red ball = 4/15
Second red ball = 3/14
total probability = First X Second
P = 4/15 * 3/14