How many different ways can you make 15 cents in change?

9 ways:

20 pennies

1 nickel 15 pennies

2 nickles 10 pennies

3 nickels 5 pennies

4 nickels

1 dime 10 pennies

1 dime 1 nickel 5 pennies

1 dime 2 nickels

2 dimes.