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

minimally, he can use 2 coins: of 10 and 25 cents.

maximally, he can use only 5 cent coins, this would be 7 coins: 7*5=35, so seven coins of 5 cents is 35 cents.

and the difference is 7-2=5

so the difference is 5!