Mary and Penelope have $296. Julie and Mary have $334. The ratio of Penelope to Julie is 1 : 3. How much does Mary have?
Amount that Penelope has = 1 u
Amount that Julie has = 3 u
The amount that Mary has is the repeated identity.
Mary + 1 u = 296 --- (1)
Mary + 3 u = 334 --- (2)
(2) - (1)
3 u - 1 u = 334 - 296
2 u = 38
1 u = 38 ÷ 2 = 19
From (1):
Mary + 1 u = 296
Mary + 1 x 19 = 296
Mary + 19 = 296
Amount that Mary has
= 296 - 19
= $277
Answer(s): $277
