Risa and Sabrina had equal amount of money. Each day, Risa spent $20 and Sabrina spent $23. When Risa had $120 left, Sabrina had
34 as much money left as Risa. How much money did the two girls have at first?
| |
Risa |
Sabrina |
| Before |
20 u + 120 |
23 u + 90 |
| Change |
- 20 u |
- 23 u |
| After |
$120 |
$90 |
Amount that Sabrina had left
=
34 x 120
= $90
The amount that Risa and Sabrina had at first is the same.
23 u + 90 = 20 u + 120
23 u - 20 u = 120 - 90
3 u = 30
1 u = 30 ÷ 3 = 10
Amount that Risa had at first
= 20 u + 120
= 20 x 10 + 120
= 200 + 120
= $320
Total amount that both girls had at first
= 2 x 320
= $640
Answer(s): $640
