PSLE
Four girls, Elyse, Zara, Yen and Lynn raised money for a charity. Elyse and Zara raised a total of $121. Together, Zara, Yen and Lynn raised a total of $194. The total amount of money raised by all 4 girls is 4 times the amount that Zara raised. How much money did Yen and Lynn raise?
Amount that Zara and Elyse raised = $121
Amount that Zara, Yen and Lynn raised = $194

Zara is the repeated identity.

Zara + Elyse = 121 --- (1)
Zara + Yen + Lynn = 194 --- (2)

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

(1) + (2)
(Zara + Elyse) + (Zara + Yen + Lynn) = 121 + 194
Zara + 4 girls = 315
1 u + 4 u = 315
5 u = 315

1 u = 315 ÷ 5 = 63

Total amount that Yen and Lynn raised
= 194 - 1 u
= 194 - 63
= $131

Answer(s): $131