Question

how many combinations of 3 can be made from 5 items

Answer 1

There are 5 ways of picking the first of the three items, leaving 4. There are 4 ways of picking the next item and 3 ways of picking the last item. So that's 5*4*3 ways. But we are only interested in the combination, not the order. So, since there are 6 ways of ordering three items we need to divide by 6: 5*4*3/6=10 combinations.