Bobby, Will and Harry had some stickers in the ratio of 3 : 4 : 7. Harry gave 40% of his stickers to Bobby and Will. As a result, Bobby had the same number of stickers as Will and Harry had 35 fewer stickers than Bobby.

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

Bobby	Will	Harry	Total
3 u	4 u	7 u	14 u
+ 2.8 u		- 2.8 u
4.9 u	4.9 u	4.2 u	14 u

(a)
Number of stickers that Harry gave away
= 40% x 7
= ⁴⁰₁₀₀ x 7
= 2.8 u

Number of stickers that Bobby and Will each had in the end
= (14 u - 4.2 u) ÷ 2
= 9.8 u ÷ 2
= 4.9 u

Increase in the number of stickers that Bobby had
= 4.9 u - 3 u
= 1.9 u

Percentage increase in Bobby's stickers after receiving from Harry
= ^1.9₃ x 100%
= 63.333333333333%

(b)
4.9 u = 4.2 u + 35
4.9 u - 4.2 u = 35
0.7 u = 35

1 u = 35 ÷ 0.7 = 50

Number of stickers that Will had at first
= 4 u
= 4 x 50
= 200

Answer(s): (a) 63.333333333333%; (b) 200