David had thrice as much money as Winnie. After David had given Winnie $131, they had an equal amount of money left. How much money did each of them have at first?
- Winnie
- David
|
Winnie |
David |
Before |
1 u |
3 u |
Change |
+ $131 |
- $131 |
After |
1 u + $131 |
3 u - $131 |
The amounts that David and Winnie had in the end are the same.
3 u - 131 = 1 u + 131
3 u - 1 u = 131 + 131
2 u = 262
1 u = 262 ÷ 2 = 131
Amount that Winnie had at first
= 1 u
= $131
Amount that David had at first
= 3 u
= 3 x 131
= $393
Answer(s): (a) $131; (b) $393