The ratio of Vincent's to Fred's money is 7 : 8. The ratio of Fred's to Simon's money is 4 : 5. If Vincent has $140, how much less does Fred have than Simon?
| Vincent |
Fred |
Simon |
| 7x1 |
8x1 |
|
| |
4x2 |
5x2 |
| 7 u |
8 u |
10 u |
The amount that Fred has is the repeated identity.
Use LCM to make it the same.
LCM of 8 and 4 = 8
Amount that Vincent has = 7 u
7 u = 140
1 u = 140 ÷ 7 = 20
Amount that Fred has less than Simon
= 10 u - 8 u
= 2 u
= 2 x 20
= $40
Answer(s): $40
