The answer to the first one is 9/4
The answer to the second one is 20/9
Hope this is right
You might be able to do direct substitution.
-- The first urn has 9 balls in it all together, and 2 of them are white.
If you don't peek, then the prob of pulling out a white ball is 2/9 .
-- The second urn has 13 balls in it all together, and 3 of them are white.
If you don't peek, then the prob of pulling out a white ball is 3/13 .
-- The probability of being successful BOTH times is
(2/9) x (3/13) = ( 6/117 ) = about 0.0513 or 5.13% (rounded)
