There are 8 books in a shelf that consist of 1 paperback books and 7 hardback books. If 3 books are selected at random without replacement, how many different combinations are there that at least one paperback book is selected?\nOptions:\n(A) 21\n(B) 45\n(C) 50\n(D) 55\n(E) 60 Stream of consciousness:
User
8C3 [Select any four] - 7C3 [Select all hard backs] = 21
Thus, the answer is (A).
Assistant