-What is the probability that they are both chocolate chip?: The probability the first is choc. chip is 5/10. After removing one choc. chip, the probability the second is choc. chip is 4/9. The probability both are choc. chip is 5/10 * 4/9 = 2/9

-What is the probability that one is peanut butter and the other is oatmeal? P(1st PB) is 3/10. P(second oat after taking away 1 PB) is 2/9. The probability is 3/10 * 2/9 = 1/15

-What is the probability that the first is peanut butter and the second is chocolate chip? P(PB) is 3/10. P(2nd choc. chip after 1 PB is removed) is 5/9. The probability is 3/10 * 5/9 = 1/6.
-What is the probability that the second is chocolate chip
given that the first is oatmeal? P(oatmeal) is 2/10. P(2nd is choc. chip after removing 1 oatmeal) is 5/9. Probability is 2/10 * 5/9 = 1/9