Tina, Cathy and Olivia had a sum of money. The amount of money Tina had was
45 of the amount of money Cathy had. The ratio of the amount of money Cathy had to the total amount of money Olivia and Cathy had was 2: 5. After Olivia gave $5 to Cathy, she had as much money as Cathy. How much more money did Olivia have than Tina in the end?
Tina |
Cathy |
Olivia |
4x2 = 8 u |
5x2 = 10 u |
|
|
2x5 = 10 u |
3x5 = 15 u |
8 u |
10 u |
15 u |
The amount that Cathy had is the repeated identity. Make the amount that Cathy had the same. LCM of 5 and 2 is 10.
|
Tina |
Cathy |
Olivia |
Before |
8 u |
10 u |
15 u |
Change |
No change |
+ 5 |
- 5 |
After |
8 u |
10 u + 5 |
15 u - 5 |
The amount that Olivia and Cathy had in the end is the same.
15 u - 5 = 10 u + 5
15 u - 10 u = 5 + 5
5 u = 10
1 u = 10 ÷ 5 = 2
Amount that Olivia had more than Tina in the end
= 15 u - 5 - 8 u
= 7 u - 5
= 7 x 2 - 5
= 14 - 5
= $9
Answer(s): $9