Tammy, Gillian and Rachel had a sum of money. The amount of money Tammy had was
45 of the amount of money Gillian had. The ratio of the amount of money Gillian had to the total amount of money Rachel and Gillian had was 2: 5. After Rachel gave $50 to Gillian, she had as much money as Gillian. How much more money did Rachel have than Tammy in the end?
Tammy |
Gillian |
Rachel |
4x2 = 8 u |
5x2 = 10 u |
|
|
2x5 = 10 u |
3x5 = 15 u |
8 u |
10 u |
15 u |
The amount that Gillian had is the repeated identity. Make the amount that Gillian had the same. LCM of 5 and 2 is 10.
|
Tammy |
Gillian |
Rachel |
Before |
8 u |
10 u |
15 u |
Change |
No change |
+ 50 |
- 50 |
After |
8 u |
10 u + 50 |
15 u - 50 |
The amount that Rachel and Gillian had in the end is the same.
15 u - 50 = 10 u + 50
15 u - 10 u = 50 + 50
5 u = 100
1 u = 100 ÷ 5 = 20
Amount that Rachel had more than Tammy in the end
= 15 u - 50 - 8 u
= 7 u - 50
= 7 x 20 - 50
= 140 - 50
= $90
Answer(s): $90