PSLE
Four girls, Eva, Roshel, Anna and Joelle raised money for a charity. Eva and Roshel raised a total of $159. Together, Roshel, Anna and Joelle raised a total of $301. The total amount of money raised by all 4 girls is 4 times the amount that Roshel raised. How much money did Roshel raise?
Amount that Roshel and Eva raised = $159
Amount that Roshel, Anna and Joelle raised = $301

Roshel is the repeated identity.

Roshel + Eva = 159 --- (1)
Roshel + Anna + Joelle = 301 --- (2)

Amount that Roshel raised = 1 u
Amount that 4 girls raised = 4 u

(1) + (2)
(Roshel + Eva) + (Roshel + Anna + Joelle) = 159 + 301
Roshel + 4 girls = 460
1 u + 4 u = 460
5 u = 460

1 u = 460 ÷ 5 = 92

Amount that Roshel raised
= 1 u
= $92

Answer(s): $92