Ben had thrice as much money as Gabby. After Ben had given Gabby $129, they had an equal amount of money left. How much money did each of them have at first?
- Gabby
- Ben
|
Gabby |
Ben |
Before |
1 u |
3 u |
Change |
+ $129 |
- $129 |
After |
1 u + $129 |
3 u - $129 |
The amounts that Ben and Gabby had in the end are the same.
3 u - 129 = 1 u + 129
3 u - 1 u = 129 + 129
2 u = 258
1 u = 258 ÷ 2 = 129
Amount that Gabby had at first
= 1 u
= $129
Amount that Ben had at first
= 3 u
= 3 x 129
= $387
Answer(s): (a) $129; (b) $387