Question

A store clerk works 4 days in a week, and doesn't work the other 3. How many different arrangements of her week are possible?

We are learning about permutations.

Answer 1

It means pick 3 in total 7:
P = 7! / ( 7 - 3) !
= 4! * 5 * 6 * 7 / 4! = 210 arrangements