PSLE
Four girls, Cathy, Fiona, Sarah and Lucy raised money for a charity. Cathy and Fiona raised a total of $176. Together, Fiona, Sarah and Lucy raised a total of $358. The total amount of money raised by all 4 girls is 5 times the amount that Fiona raised. How much money did Sarah and Lucy raise?
Amount that Fiona and Cathy raised = $176
Amount that Fiona, Sarah and Lucy raised = $358

Fiona is the repeated identity.

Fiona + Cathy = 176 --- (1)
Fiona + Sarah + Lucy = 358 --- (2)

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

(1) + (2)
(Fiona + Cathy) + (Fiona + Sarah + Lucy) = 176 + 358
Fiona + 4 girls = 534
1 u + 5 u = 534
6 u = 534

1 u = 534 ÷ 6 = 89

Total amount that Sarah and Lucy raised
= 358 - 1 u
= 358 - 89
= $269

Answer(s): $269