Bobby and Zeph have some money. If Bobby gives $385 to Zeph, the ratio of their money will be 3 : 5. If Bobby gives $602 to Zeph, the ratio of their money will be 1: 4. How much does Bobby have?
| |
Case 1 |
Case 2 |
| |
Bobby |
Zeph |
Bobby |
Zeph |
| Before |
15 u + $385 |
25 u - $385 |
8 u + $602 |
32 u - $602 |
| Change |
- $385 |
+ $385 |
- $602 |
+ $602 |
After
|
3x5 =
15 u |
5x5 =
25 u |
1x8 =
8 u |
4x8 =
32 u |
The total amounts in both cases remain unchanged. Make the total amounts in both cases the same. LCM of 8 and 5 is 40.
The amount that Bobby has at first is the same in both cases.
15 u + 385 = 8 u + 602
15 u - 8 u = 602 - 385
7 u = 217
1 u = 217 ÷ 7 = 31
Amount that Bobby has
= 15 u + 385
= 15 x 31 + 385
= 465 + 385
= $850
Answer(s): $850
