find the probability

Question

a bag contain 3 red, 6 white and 7 blue balls. What is the probability that two balls drawn are not white or blue.

Answer 1

There are 16 balls in all. If the drawn balls are not white or blue they must be red.

The probability of drawing a red ball is 3/16, leaving 15 balls, 2 of which are red.

The probability of drawing another red ball is 2/15.

The combined probability is (3/16)(2/15)=(3/15)(2/16)=⅕×⅛=1/40.