Given are all the possible 10 number combinations (NOT permutations) of the numbers 11 - 26 (8008 combinations), and 4 random numbers from the 11 - 26 sequence.

How do I find out how many of the 8008 combinations contain

a. all 4 random numbers?

b. 3 of the 4, 2 of the 4, 1 of the 4 and 0 of the 4 random numbers respectively??