The ratio of Ahmad's to Sam's money is 5 : 4. The ratio of Sam's to David's money is 3 : 4. If Ahmad has $255, how much more does David have than Sam?
| Ahmad |
Sam |
David |
| 5x3 |
4x3 |
|
| |
3x4 |
4x4 |
| 15 u |
12 u |
16 u |
The amount that Sam has is the repeated identity.
Use LCM to make it the same.
LCM of 4 and 3 = 12
Amount that Ahmad has = 15 u
15 u = 255
1 u = 255 ÷ 15 = 17
Amount that David has more than Sam
= 16 u - 12 u
= 4 u
= 4 x 17
= $68
Answer(s): $68
