PSLE
Four girls, Elyse, Abi, Emily and Nicole raised money for a charity. Elyse and Abi raised a total of $131. Together, Abi, Emily and Nicole raised a total of $237. The total amount of money raised by all 4 girls is 3 times the amount that Abi raised. How much money did Emily and Nicole raise?
Amount that Abi and Elyse raised = $131
Amount that Abi, Emily and Nicole raised = $237

Abi is the repeated identity.

Abi + Elyse = 131 --- (1)
Abi + Emily + Nicole = 237 --- (2)

Amount that Abi raised = 1 u
Amount that 4 girls raised = 3 u

(1) + (2)
(Abi + Elyse) + (Abi + Emily + Nicole) = 131 + 237
Abi + 4 girls = 368
1 u + 3 u = 368
4 u = 368

1 u = 368 ÷ 4 = 92

Total amount that Emily and Nicole raised
= 237 - 1 u
= 237 - 92
= $145

Answer(s): $145