Lee and Ahmad have some money. If Lee gives $138 to Ahmad, the ratio of their money will be 2 : 5. If Lee gives $651 to Ahmad, the ratio of their money will be 1: 4. How much does Lee have?
| |
Case 1 |
Case 2 |
| |
Lee |
Ahmad |
Lee |
Ahmad |
| Before |
10 u + $138 |
25 u - $138 |
7 u + $651 |
28 u - $651 |
| Change |
- $138 |
+ $138 |
- $651 |
+ $651 |
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 Lee has at first is the same in both cases.
10 u + 138 = 7 u + 651
10 u - 7 u = 651 - 138
3 u = 513
1 u = 513 ÷ 3 = 171
Amount that Lee has
= 10 u + 138
= 10 x 171 + 138
= 1710 + 138
= $1848
Answer(s): $1848
