Question

Paul owes Paula 35 cents and has a pocket full of 5-cent coins, 10-cent coins, and 25-cent coins that he can use to pay her. What is the difference between the largest and the smallest number of coins he can use to pay her?

Answer 1

The smallest possible number would be 1, if there were a 35 cents coin, but since there isn't: it's 2: 25+10 cents coins.

The biggest number of coins would be 7, that is if you use the smallest coins of only 5 cents: because 5*7=35

and the difference is 5 coins: 7-2=5