Glen, Lee and Jeremy had some marbles in the ratio of 2 : 3 : 5. Jeremy gave 40% of his marbles to Glen and Lee. As a result, Glen had the same number of marbles as Lee and Jeremy had 31 fewer marbles than Glen.

1. What was the percentage increase in Glen's marbles after receiving from Jeremy?
2. How many marbles did Lee have at first?

Glen	Lee	Jeremy	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 marbles that Jeremy gave away
= 40% x 5
= ⁴⁰₁₀₀ x 5
= 2 u

Number of marbles that Glen and Lee each had in the end
= (10 u - 3 u) ÷ 2
= 7 u ÷ 2
= 3.5 u

Increase in the number of marbles that Glen had
= 3.5 u - 2 u
= 1.5 u

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

(b)
3.5 u = 3 u + 31
3.5 u - 3 u = 31
0.5 u = 31

1 u = 31 ÷ 0.5 = 62

Number of marbles that Lee had at first
= 3 u
= 3 x 62
= 186

Answer(s): (a) 75%; (b) 186