Dylan, Jack and Harry had some stickers in the ratio of 2 : 3 : 5. Harry gave 40% of his stickers to Dylan and Jack. As a result, Dylan had the same number of stickers as Jack and Harry had 28 fewer stickers than Dylan.

1. What was the percentage increase in Dylan's stickers after receiving from Harry?
2. How many stickers did Jack have at first?

Dylan	Jack	Harry	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 stickers that Harry gave away
= 40% x 5
= ⁴⁰₁₀₀ x 5
= 2 u

Number of stickers that Dylan and Jack each had in the end
= (10 u - 3 u) ÷ 2
= 7 u ÷ 2
= 3.5 u

Increase in the number of stickers that Dylan had
= 3.5 u - 2 u
= 1.5 u

Percentage increase in Dylan's stickers after receiving from Harry
= ^1.5₂ x 100%
= 75%

(b)
3.5 u = 3 u + 28
3.5 u - 3 u = 28
0.5 u = 28

1 u = 28 ÷ 0.5 = 56

Number of stickers that Jack had at first
= 3 u
= 3 x 56
= 168

Answer(s): (a) 75%; (b) 168