(1) The probability is 1/C(20,3) = 1/1140.
(2)
Case 1: Superball
The probability is 1/10, because you choose 1 out of 10.
Case 2: 2 whites
The probability is 1/C(10,2) = 1/45, because you choose 2 out of 10.
Case 3: 3 whites
The probability is 1/C(10,3) = 1/120, because you choose 3 out of 10.
Adding these, you get 1/10 + 1/45 + 1/120 = 47/360.