Oscar and Peter have some money. If Oscar gives $388 to Peter, the ratio of their money will be 2 : 5. If Oscar gives $478 to Peter, the ratio of their money will be 1: 4. How much does Oscar have?
| |
Case 1 |
Case 2 |
| |
Oscar |
Peter |
Oscar |
Peter |
| Before |
10 u + $388 |
25 u - $388 |
7 u + $478 |
28 u - $478 |
| Change |
- $388 |
+ $388 |
- $478 |
+ $478 |
After
|
2x5 =
10 u |
5x5 =
25 u |
1x7 =
7 u |
4x7 =
28 u |
The total amounts in both cases remain unchanged. Make the total amounts in both cases the same. LCM of 7 and 5 is 35.
The amount that Oscar has at first is the same in both cases.
10 u + 388 = 7 u + 478
10 u - 7 u = 478 - 388
3 u = 90
1 u = 90 ÷ 3 = 30
Amount that Oscar has
= 10 u + 388
= 10 x 30 + 388
= 300 + 388
= $688
Answer(s): $688
