Apply Counting Principle to Compute Combinations and Permutations

There are 5 students who work in a bookshop. If the bookshop needs 3 people to operate, how many days straight could the bookshop operate without the same group of students working twice?


Combinations of n objects taken r at a time:

The number of combinations of r objects taken from a group of n distinct objects is denoted by nCr and is given by the formula: nCr=\frac{n!}{(n-r)!r!}





10 days