Mary and Gillian have $219. Lucy and Mary have $236. The ratio of Gillian to Lucy is 2 : 3. How much does Mary have?
Amount that Gillian has = 2 u
Amount that Lucy has = 3 u
The amount that Mary has is the repeated identity.
Mary + 2 u = 219 --- (1)
Mary + 3 u = 236 --- (2)
(2) - (1)
3 u - 2 u = 236 - 219
1 u = 17
From (1):
Mary + 2 u = 219
Mary + 2 x 17 = 219
Mary + 34 = 219
Amount that Mary has
= 219 - 34
= $185
Answer(s): $185
