Zara and Jane have $310. Risa and Zara have $361. The ratio of Jane to Risa is 4 : 7. How much does Zara have?
Amount that Jane has = 4 u
Amount that Risa has = 7 u
The amount that Zara has is the repeated identity.
Zara + 4 u = 310 --- (1)
Zara + 7 u = 361 --- (2)
(2) - (1)
7 u - 4 u = 361 - 310
3 u = 51
1 u = 51 ÷ 3 = 17
From (1):
Zara + 4 u = 310
Zara + 4 x 17 = 310
Zara + 68 = 310
Amount that Zara has
= 310 - 68
= $242
Answer(s): $242
