The ratio of Liam's to David's money is 7 : 3. The ratio of David's to Ian's money is 3 : 5. If Liam has $77, how much more does Ian have than David?
| Liam |
David |
Ian |
| 7x1 |
3x1 |
|
| |
3x1 |
5x1 |
| 7 u |
3 u |
5 u |
The amount that David has is the repeated identity.
Use LCM to make it the same.
LCM of 3 and 3 = 3
Amount that Liam has = 7 u
7 u = 77
1 u = 77 ÷ 7 = 11
Amount that Ian has more than David
= 5 u - 3 u
= 2 u
= 2 x 11
= $22
Answer(s): $22
