If you have a 5c, 10c and 20c coins, in how many ways can you make up 45cents?

[adam]

Please Help, I'm really stuck on this questions,

Thanks.
x

 

[JeJe]

9 different ways

2 x 20, 1x5
1 x 20, 2x 10, 1 x 5
1 x 20, 1 x 10, 3 x 5
1 x 20, 5 x 5
4 x 10, 1 x 5
3 x 10, 3 x 5
2 x 10, 5 x 5
1 x 10, 7 x 5
9 x 5