Flynn, Jenson and Oliver had some stamps in the ratio of 3 : 4 : 7. Oliver gave 40% of his stamps to Flynn and Jenson. As a result, Flynn had the same number of stamps as Jenson and Oliver had 42 fewer stamps than Flynn.

1. What was the percentage increase in Flynn's stamps after receiving from Oliver?
2. How many stamps did Jenson have at first?

Flynn	Jenson	Oliver	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 stamps that Oliver gave away
= 40% x 7
= ⁴⁰₁₀₀ x 7
= 2.8 u

Number of stamps that Flynn and Jenson each had in the end
= (14 u - 4.2 u) ÷ 2
= 9.8 u ÷ 2
= 4.9 u

Increase in the number of stamps that Flynn had
= 4.9 u - 3 u
= 1.9 u

Percentage increase in Flynn's stamps after receiving from Oliver
= ^1.9₃ x 100%
= 63.333333333333%

(b)
4.9 u = 4.2 u + 42
4.9 u - 4.2 u = 42
0.7 u = 42

1 u = 42 ÷ 0.7 = 60

Number of stamps that Jenson had at first
= 4 u
= 4 x 60
= 240

Answer(s): (a) 63.333333333333%; (b) 240