How many different ways can you make 50p using 5p, 10p or 20p coins?

Question

If you have sticks which measure 1, 2, 3, 4, 5, 6, 7, 8 and 9 cm (one of each). How many different triangles can you make using three of the sticks?

Answer 1

> Total 12 different ways.

1. include two 20p coin - remaining are 10p can be completed by 2 ways ( include one or zero 10p coin ) -->> 2 methods
2. include one 20p coin - remaining are 30p can be completed by 4 ways ( include three or two or one or zero 10p coin ) -->> 4 methods
3. include zero 20p coin - remaining are 50p can be completed by 6 ways ( include 5/4/3/2/1/0 - 10p coin ) -->> 6 methods
   Total 2+4+6 = 12 methods.