Lucy and Cindy have $164. Gillian and Lucy have $203. The ratio of Cindy to Gillian is 4 : 7. How much does Lucy have?
Amount that Cindy has = 4 u
Amount that Gillian has = 7 u
The amount that Lucy has is the repeated identity.
Lucy + 4 u = 164 --- (1)
Lucy + 7 u = 203 --- (2)
(2) - (1)
7 u - 4 u = 203 - 164
3 u = 39
1 u = 39 ÷ 3 = 13
From (1):
Lucy + 4 u = 164
Lucy + 4 x 13 = 164
Lucy + 52 = 164
Amount that Lucy has
= 164 - 52
= $112
Answer(s): $112
