Two urns contain white balls and yellow balls The first urn

Two urns contain white balls and yellow balls. The first urn contains 3 white balls and 6 yellow balls and the second urn contains 3 white balls and 8 yellow balls. A ball is drawn at random from each urn. What is the probability that both balls are white? A. 2/33 B. 1/9 C. 1/11 D. 3/10

Solution

The first urn contains 3 white balls and 6 yellow balls. Total balls in this urn = 3+6= 09

Prob of getting white from this earn = 3/9

The second urn contains 3 white balls and 8 yellow balls. Total balls in this urn = 3+8= 11

Prob of getting white from this earn = 3/11

Prob of choosing 1st or 2nd earn urn = 1/2

By applying condition prob:

P( both balls are whte) = .5*(3/9) +.5(3/11) = 1,5(20/99) = 30/99 = 10/33

This is the right answer, the options presented here don\'t seem to be the right answer.