Irene and Lynn have $209. Zoe and Irene have $245. The ratio of Lynn to Zoe is 1 : 4. How much does Irene have?
Amount that Lynn has = 1 u
Amount that Zoe has = 4 u
The amount that Irene has is the repeated identity.
Irene + 1 u = 209 --- (1)
Irene + 4 u = 245 --- (2)
(2) - (1)
4 u - 1 u = 245 - 209
3 u = 36
1 u = 36 ÷ 3 = 12
From (1):
Irene + 1 u = 209
Irene + 1 x 12 = 209
Irene + 12 = 209
Amount that Irene has
= 209 - 12
= $197
Answer(s): $197
