PSLE
Gillian and Jaslyn went shopping together with a total amount of $119.40. Gillian spent 2 times as much as Jaslyn. The amount Jaslyn had left was $31 more than what she had spent. She had 2 times as much money left as Gillian.
(a) How much money did Jaslyn spend?
(b) How much money did Gillian have at first?

	Gillian	Jaslyn	Total
Before	2.5 u + 15.5	2 u + 31	119.40
Change	- 2 u	- 1 u
After	0.5 u + 15.5	1 u + 31

(a)
Total amount that Gillian and Jaslyn had at first
= (2.5 u + 15.5) + (2 u + 31)
= 2.5 u + 2 u + 15.5 + 31
= 4.5 u + 46.5

4.5 u + 46.5 = 119.4
4.5 u = 119.4 - 46.5
4.5 u = 72.9

1 u = 72.9 ÷ 4.5 = 16.2

Amount that Jaslyn had at first
= 1 u
= $16.20

(b)
Amount that Gillian had at first
= 2.5 u + 15.5
= (2.5 x 16.2) + 15.5
= 40.5 + 15.5
= $56

Answer(s): (a) $16.20; (b) $56