The ratio of Sean's to Billy's money is 4 : 7. The ratio of Billy's to Jack's money is 3 : 4. If Sean has $156, how much more does Jack have than Billy?
| Sean |
Billy |
Jack |
| 4x3 |
7x3 |
|
| |
3x7 |
4x7 |
| 12 u |
21 u |
28 u |
The amount that Billy has is the repeated identity.
Use LCM to make it the same.
LCM of 7 and 3 = 21
Amount that Sean has = 12 u
12 u = 156
1 u = 156 ÷ 12 = 13
Amount that Jack has more than Billy
= 28 u - 21 u
= 7 u
= 7 x 13
= $91
Answer(s): $91
