PSLE
Four girls, Vanessa, Yen, Mary and Diana raised money for a charity. Vanessa and Yen raised a total of $149. Together, Yen, Mary and Diana raised a total of $211. The total amount of money raised by all 4 girls is 4 times the amount that Yen raised. How much money did Yen raise?
Amount that Yen and Vanessa raised = $149
Amount that Yen, Mary and Diana raised = $211

Yen is the repeated identity.

Yen + Vanessa = 149 --- (1)
Yen + Mary + Diana = 211 --- (2)

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

(1) + (2)
(Yen + Vanessa) + (Yen + Mary + Diana) = 149 + 211
Yen + 4 girls = 360
1 u + 4 u = 360
5 u = 360

1 u = 360 ÷ 5 = 72

Amount that Yen raised
= 1 u
= $72

Answer(s): $72