Cole, Jeremy and Riordan had some cards in the ratio of 2 : 3 : 5. Riordan gave 40% of his cards to Cole and Jeremy. As a result, Cole had the same number of cards as Jeremy and Riordan had 30 fewer cards than Cole.

1. What was the percentage increase in Cole's cards after receiving from Riordan?
2. How many cards did Jeremy have at first?

Cole	Jeremy	Riordan	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 cards that Riordan gave away
= 40% x 5
= ⁴⁰₁₀₀ x 5
= 2 u

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

Increase in the number of cards that Cole had
= 3.5 u - 2 u
= 1.5 u

Percentage increase in Cole's cards after receiving from Riordan
= ^1.5₂ x 100%
= 75%

(b)
3.5 u = 3 u + 30
3.5 u - 3 u = 30
0.5 u = 30

1 u = 30 ÷ 0.5 = 60

Number of cards that Jeremy had at first
= 3 u
= 3 x 60
= 180

Answer(s): (a) 75%; (b) 180