Peter and Luis have some money. If Peter gives $387 to Luis, the ratio of their money will be 2 : 5. If Peter gives $525 to Luis, the ratio of their money will be 1: 4. How much does Peter have?
| |
Case 1 |
Case 2 |
| |
Peter |
Luis |
Peter |
Luis |
| Before |
10 u + $387 |
25 u - $387 |
7 u + $525 |
28 u - $525 |
| Change |
- $387 |
+ $387 |
- $525 |
+ $525 |
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 Peter has at first is the same in both cases.
10 u + 387 = 7 u + 525
10 u - 7 u = 525 - 387
3 u = 138
1 u = 138 ÷ 3 = 46
Amount that Peter has
= 10 u + 387
= 10 x 46 + 387
= 460 + 387
= $847
Answer(s): $847
