Betty and Penelope have $188. Natalie and Betty have $244. The ratio of Penelope to Natalie is 3 : 7. How much does Betty have?
Amount that Penelope has = 3 u
Amount that Natalie has = 7 u
The amount that Betty has is the repeated identity.
Betty + 3 u = 188 --- (1)
Betty + 7 u = 244 --- (2)
(2) - (1)
7 u - 3 u = 244 - 188
4 u = 56
1 u = 56 ÷ 4 = 14
From (1):
Betty + 3 u = 188
Betty + 3 x 14 = 188
Betty + 42 = 188
Amount that Betty has
= 188 - 42
= $146
Answer(s): $146
