The ratio of Ethan's to Sam's money is 7 : 8. The ratio of Sam's to Oscar's money is 4 : 5. If Ethan has $91, how much less does Sam have than Oscar?
Ethan |
Sam |
Oscar |
7x1 |
8x1 |
|
|
4x2 |
5x2 |
7 u |
8 u |
10 u |
The amount that Sam has is the repeated identity.
Use LCM to make it the same.
LCM of 8 and 4 = 8
Amount that Ethan has = 7 u
7 u = 91
1 u = 91 ÷ 7 = 13
Amount that Sam has less than Oscar
= 10 u - 8 u
= 2 u
= 2 x 13
= $26
Answer(s): $26