how many ways can 8 dollars be changed to dimes and/or quarters

Answer 1

8 = 10D + 25Q

32 quarters and zero dimes

30 quarters and 5 dimes

28 quarters and 10 dimes

26 quarters and 15 dimes

24 quarters and 20 dimes

... etc.

2 quarters and 75 dimes

0 quarters and 80 dimes

17 total ways, dimes have to be a multiple of 5, quarters have to be an even number

32/2= 16 add one to get 17 ways

or

80/5 = 16 plus one = 17 ways