Jeremy, Archie and Caden had some stamps in the ratio of 2 : 3 : 5. Caden gave 40% of his stamps to Jeremy and Archie. As a result, Jeremy had the same number of stamps as Archie and Caden had 16 fewer stamps than Jeremy.

1. What was the percentage increase in Jeremy's stamps after receiving from Caden?
2. How many stamps did Archie have at first?

Jeremy	Archie	Caden	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 Caden gave away
= 40% x 5
= ⁴⁰₁₀₀ x 5
= 2 u

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

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

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

(b)
3.5 u = 3 u + 16
3.5 u - 3 u = 16
0.5 u = 16

1 u = 16 ÷ 0.5 = 32

Number of stamps that Archie had at first
= 3 u
= 3 x 32
= 96

Answer(s): (a) 75%; (b) 96