Question

Prove that it is possible to pay any debt of $4, $5, $6, $7, ... $n and so on, by using only $2 bills and $5 bills. For example, a debt of $11 can be paid with three $2 bills and one $5 bills or $11= 3 x $2 +1 x $5

Answer 1

Step 1: Any even number can be made up of $2 bills.
Step 2 part 1: Any odd number can be made into an even number by subtracting $5.
Step 2 part 2: See Step 1.

Answer 2

thank you