Thread: Vending machine problem

Hey guys here's my problem:
A vending machine takes 10, 20 and 50 cent coins only.
In how many ways can we put n cents in the machine provided that n is a multiple of 10(i.e. n =10*k, where )

Sorry for the bump here, but I was also wondering how i could relate this problem to the Coin Problem:
Coin Problem -- from Wolfram MathWorld