The ratio of Riordan's to Elijah's money is 7 : 9. The ratio of Elijah's to Billy's money is 4 : 5. If Riordan has $448, how much more does Billy have than Elijah?
| Riordan |
Elijah |
Billy |
| 7x4 |
9x4 |
|
| |
4x9 |
5x9 |
| 28 u |
36 u |
45 u |
The amount that Elijah has is the repeated identity.
Use LCM to make it the same.
LCM of 9 and 4 = 36
Amount that Riordan has = 28 u
28 u = 448
1 u = 448 ÷ 28 = 16
Amount that Billy has more than Elijah
= 45 u - 36 u
= 9 u
= 9 x 16
= $144
Answer(s): $144
