The ratio of Seth's to Ethan's money is 3 : 5. The ratio of Ethan's to Cody's money is 3 : 4. If Seth has $180, how much less does Ethan have than Cody?
| Seth |
Ethan |
Cody |
| 3x3 |
5x3 |
|
| |
3x5 |
4x5 |
| 9 u |
15 u |
20 u |
The amount that Ethan has is the repeated identity.
Use LCM to make it the same.
LCM of 5 and 3 = 15
Amount that Seth has = 9 u
9 u = 180
1 u = 180 ÷ 9 = 20
Amount that Ethan has less than Cody
= 20 u - 15 u
= 5 u
= 5 x 20
= $100
Answer(s): $100
