PSLE
Four girls, Xuan, Fiona, Cindy and Zara raised money for a charity. Xuan and Fiona raised a total of $128. Together, Fiona, Cindy and Zara raised a total of $304. The total amount of money raised by all 4 girls is 5 times the amount that Fiona raised. How much money did Cindy and Zara raise?
Amount that Fiona and Xuan raised = $128
Amount that Fiona, Cindy and Zara raised = $304

Fiona is the repeated identity.

Fiona + Xuan = 128 --- (1)
Fiona + Cindy + Zara = 304 --- (2)

Amount that Fiona raised = 1 u
Amount that 4 girls raised = 5 u

(1) + (2)
(Fiona + Xuan) + (Fiona + Cindy + Zara) = 128 + 304
Fiona + 4 girls = 432
1 u + 5 u = 432
6 u = 432

1 u = 432 ÷ 6 = 72

Total amount that Cindy and Zara raised
= 304 - 1 u
= 304 - 72
= $232

Answer(s): $232