Opal and Irene have $188. Zoe and Opal have $221. The ratio of Irene to Zoe is 2 : 5. How much does Opal have?
Amount that Irene has = 2 u
Amount that Zoe has = 5 u
The amount that Opal has is the repeated identity.
Opal + 2 u = 188 --- (1)
Opal + 5 u = 221 --- (2)
(2) - (1)
5 u - 2 u = 221 - 188
3 u = 33
1 u = 33 ÷ 3 = 11
From (1):
Opal + 2 u = 188
Opal + 2 x 11 = 188
Opal + 22 = 188
Amount that Opal has
= 188 - 22
= $166
Answer(s): $166
