Gwen and Gabby had equal amount of money. Each day, Gwen spent $9 and Gabby spent $11. When Gwen had $90 left, Gabby had
79 as much money left as Gwen. How much money did the two girls have at first?
| |
Gwen |
Gabby |
| Before |
9 u + 90 |
11 u + 70 |
| Change |
- 9 u |
- 11 u |
| After |
$90 |
$70 |
Amount that Gabby had left
=
79 x 90
= $70
The amount that Gwen and Gabby had at first is the same.
11 u + 70 = 9 u + 90
11 u - 9 u = 90 - 70
2 u = 20
1 u = 20 ÷ 2 = 10
Amount that Gwen had at first
= 9 u + 90
= 9 x 10 + 90
= 90 + 90
= $180
Total amount that both girls had at first
= 2 x 180
= $360
Answer(s): $360
