Kathy and Lucy had equal amount of money. Each day, Kathy spent $7 and Lucy spent $9. When Kathy had $120 left, Lucy had
12 as much money left as Kathy. How much money did the two girls have at first?
| |
Kathy |
Lucy |
| Before |
7 u + 120 |
9 u + 60 |
| Change |
- 7 u |
- 9 u |
| After |
$120 |
$60 |
Amount that Lucy had left
=
12 x 120
= $60
The amount that Kathy and Lucy had at first is the same.
9 u + 60 = 7 u + 120
9 u - 7 u = 120 - 60
2 u = 60
1 u = 60 ÷ 2 = 30
Amount that Kathy had at first
= 7 u + 120
= 7 x 30 + 120
= 210 + 120
= $330
Total amount that both girls had at first
= 2 x 330
= $660
Answer(s): $660
