The ratio of Henry's to Riordan's money is 7 : 5. The ratio of Riordan's to Archie's money is 4 : 5. If Henry has $504, how much less does Riordan have than Archie?
| Henry |
Riordan |
Archie |
| 7x4 |
5x4 |
|
| |
4x5 |
5x5 |
| 28 u |
20 u |
25 u |
The amount that Riordan has is the repeated identity.
Use LCM to make it the same.
LCM of 5 and 4 = 20
Amount that Henry has = 28 u
28 u = 504
1 u = 504 ÷ 28 = 18
Amount that Riordan has less than Archie
= 25 u - 20 u
= 5 u
= 5 x 18
= $90
Answer(s): $90
