Question

Two urns contain white balls and yellow balls. The first urn contains 2 white balls and 7 yellow balls and the second urn contains 10 white balls and 4 yellow balls. A ball is drawn at random from each urn. What is the probability that both balls are white?

Answer 1

The first one has 2 white balls out of 9 total.
The probability of pulling a white ball from it is  2/9 .  (about 22.2%)

The second one has 10 white balls out of 14 total.
The probability of pulling a white ball from it is  10/14.  (about 71.4%)

The probability of both of these things happening is

             (2/9) x (10/14)  =  20/126  =  10/63  =  about  15.9%  (rounded)