...ok. The odds of getting the first 6 are obviously 1/6. The odds of getting it the second time are still 1/6. So getting two sixes is (1/6)(1/6) = 1/36...and so on.
Part b is a gimme as soon as you get part a.
Part c is simple.
Just write out every possibility.
A1 vs B1
A1 vs B2
...
A3 vs B3
Then determine how many of them fit the conditions.
This one is tougher, but you just have to know that diamonds are 13/52 cards. If one gets picked, then diamonds are 12/51 cards. If not, diamonds are 13/51 cards.