Billy, George and Wesley had some stamps in the ratio of 2 : 3 : 5. Wesley gave 40% of his stamps to Billy and George. As a result, Billy had the same number of stamps as George and Wesley had 20 fewer stamps than Billy.

1. What was the percentage increase in Billy's stamps after receiving from Wesley?
2. How many stamps did George have at first?

Billy	George	Wesley	Total
2 u	3 u	5 u	10 u
+ 2 u		- 2 u
3.5 u	3.5 u	3 u	10 u

(a)
Number of stamps that Wesley gave away
= 40% x 5
= ⁴⁰₁₀₀ x 5
= 2 u

Number of stamps that Billy and George each had in the end
= (10 u - 3 u) ÷ 2
= 7 u ÷ 2
= 3.5 u

Increase in the number of stamps that Billy had
= 3.5 u - 2 u
= 1.5 u

Percentage increase in Billy's stamps after receiving from Wesley
= ^1.5₂ x 100%
= 75%

(b)
3.5 u = 3 u + 20
3.5 u - 3 u = 20
0.5 u = 20

1 u = 20 ÷ 0.5 = 40

Number of stamps that George had at first
= 3 u
= 3 x 40
= 120

Answer(s): (a) 75%; (b) 120