The ratio of Lee's to Sean's money is 3 : 5. The ratio of Sean's to David's money is 3 : 4. If Lee has $108, how much more does David have than Sean?
| Lee |
Sean |
David |
| 3x3 |
5x3 |
|
| |
3x5 |
4x5 |
| 9 u |
15 u |
20 u |
The amount that Sean has is the repeated identity.
Use LCM to make it the same.
LCM of 5 and 3 = 15
Amount that Lee has = 9 u
9 u = 108
1 u = 108 ÷ 9 = 12
Amount that David has more than Sean
= 20 u - 15 u
= 5 u
= 5 x 12
= $60
Answer(s): $60
