Post a New Question

posted by Ashley Friday, February 28, 2014 at 4:43pm.

There are 7 different books on a shelf. How many selections of more than 4 books can be made?

7C4 + 7C5 + 7C6 + 7C7 = 64 since n ∑ nCk = 2^n k=0

More Related Questions