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

1. What was the percentage increase in Tim's stickers after receiving from Zeph?
2. How many stickers did Oscar have at first?

Tim	Oscar	Zeph	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 Zeph gave away
= 40% x 7
= ⁴⁰₁₀₀ x 7
= 2.8 u

Number of stickers that Tim and Oscar 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 Tim had
= 4.9 u - 3 u
= 1.9 u

Percentage increase in Tim's stickers after receiving from Zeph
= ^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 Oscar had at first
= 4 u
= 4 x 50
= 200

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