PSLE
Marion and Gillian went shopping together with a total amount of $125.40. Marion spent 2 times as much as Gillian. The amount Gillian had left was $35 more than what she had spent. She had 2 times as much money left as Marion.
(a) How much money did Gillian spend?
(b) How much money did Marion have at first?

	Marion	Gillian	Total
Before	2.5 u + 17.5	2 u + 35	125.40
Change	- 2 u	- 1 u
After	0.5 u + 17.5	1 u + 35

(a)
Total amount that Marion and Gillian had at first
= (2.5 u + 17.5) + (2 u + 35)
= 2.5 u + 2 u + 17.5 + 35
= 4.5 u + 52.5

4.5 u + 52.5 = 125.4
4.5 u = 125.4 - 52.5
4.5 u = 72.9

1 u = 72.9 ÷ 4.5 = 16.2

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

(b)
Amount that Marion had at first
= 2.5 u + 17.5
= (2.5 x 16.2) + 17.5
= 40.5 + 17.5
= $58

Answer(s): (a) $16.20; (b) $58