PSLERisa and Gabby went shopping together with a total amount of $131.40. Risa spent 2 times as much as Gabby. The amount Gabby had left was $33 more than what she had spent. She had 2 times as much money left as Risa.
(a) How much money did Gabby spend?
(b) How much money did Risa have at first?
|
Risa |
Gabby |
Total |
Before |
2.5 u + 16.5 |
2 u + 33 |
131.40 |
Change |
- 2 u |
- 1 u |
|
After |
0.5 u + 16.5 |
1 u + 33 |
|
(a)
Total amount that Risa and Gabby had at first
= (2.5 u + 16.5) + (2 u + 33)
= 2.5 u + 2 u + 16.5 + 33
= 4.5 u + 49.5
4.5 u + 49.5 = 131.4
4.5 u = 131.4 - 49.5
4.5 u = 81.9
1 u = 81.9 ÷ 4.5 = 18.2
Amount that Gabby had at first
= 1 u
= $18.20
(b)
Amount that Risa had at first
= 2.5 u + 16.5
= (2.5 x 18.2) + 16.5
= 45.5 + 16.5
= $62
Answer(s): (a) $18.20; (b) $62