Question

Nolan had 20 dimes it takes three dimes to buy a pencil from the vending machine Nolan bought more than one pencil how many dimes does he have left

Answer 1

He should have a total of two dimes left

Answer 2

20 dimes/3 dimes = 6(pencils)+ 2 dimes left over  
Check: 3*6=18 dimes were spend
!8+2=20 dimes were at first.

in general,
if he bought x pencils
3x- he spend on pencils 
(20-3x) - dimes left