Gabriel, Zane and David had some coins in the ratio of 2 : 3 : 5. David gave 40% of his coins to Gabriel and Zane. As a result, Gabriel had the same number of coins as Zane and David had 29 fewer coins than Gabriel.

1. What was the percentage increase in Gabriel's coins after receiving from David?
2. How many coins did Zane have at first?

Gabriel	Zane	David	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 coins that David gave away
= 40% x 5
= ⁴⁰₁₀₀ x 5
= 2 u

Number of coins that Gabriel and Zane each had in the end
= (10 u - 3 u) ÷ 2
= 7 u ÷ 2
= 3.5 u

Increase in the number of coins that Gabriel had
= 3.5 u - 2 u
= 1.5 u

Percentage increase in Gabriel's coins after receiving from David
= ^1.5₂ x 100%
= 75%

(b)
3.5 u = 3 u + 29
3.5 u - 3 u = 29
0.5 u = 29

1 u = 29 ÷ 0.5 = 58

Number of coins that Zane had at first
= 3 u
= 3 x 58
= 174

Answer(s): (a) 75%; (b) 174