Jack, Albert and Henry had some stamps in the ratio of 2 : 3 : 5. Henry gave 40% of his stamps to Jack and Albert. As a result, Jack had the same number of stamps as Albert and Henry had 37 fewer stamps than Jack.

1. What was the percentage increase in Jack's stamps after receiving from Henry?
2. How many stamps did Albert have at first?

Jack	Albert	Henry	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 Henry gave away
= 40% x 5
= ⁴⁰₁₀₀ x 5
= 2 u

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

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

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

(b)
3.5 u = 3 u + 37
3.5 u - 3 u = 37
0.5 u = 37

1 u = 37 ÷ 0.5 = 74

Number of stamps that Albert had at first
= 3 u
= 3 x 74
= 222

Answer(s): (a) 75%; (b) 222