David had $390 more than Oscar at first. David gave $90 to Oscar. As a result, Oscar has
58 as much money as David. How much money had each of them at first?
- David
- Oscar
| |
David |
Oscar |
More |
| Before |
8 u + $90 |
5 u - $90 |
$390 |
| Change |
- $90 |
+ $90 |
|
| After |
8 u |
5 u |
|
(a)
David had $390 more than Oscar at first. If Oscar received another $390, David and Oscar would have the same amount at first.
8 u + 90 = 5 u - 90 + 390
8 u + 90 = 5 u + 300
8 u - 5 u = 300 - 90
3 u = 210
1 u = 210 ÷ 3 = 70
Amount that David had at first
= 8 u + 90
= 8 x 70 + 90
= 560 + 90
= $650
(b)
Amount that Oscar had at first
= 5 u - 90
= 5 x 70 - 90
= 350 - 90
= $260
Answer(s): (a) $650; (b) $260
