The ratio of David's to Peter's money is 7 : 9. The ratio of Peter's to Glen's money is 3 : 4. If David has $140, how much less does Peter have than Glen?
| David |
Peter |
Glen |
| 7x1 |
9x1 |
|
| |
3x3 |
4x3 |
| 7 u |
9 u |
12 u |
The amount that Peter has is the repeated identity.
Use LCM to make it the same.
LCM of 9 and 3 = 9
Amount that David has = 7 u
7 u = 140
1 u = 140 ÷ 7 = 20
Amount that Peter has less than Glen
= 12 u - 9 u
= 3 u
= 3 x 20
= $60
Answer(s): $60
