Tiffany and Roshel have some money. If Tiffany spends $20, she will have
25 as much money as Roshel. If Roshel spends $6, Tiffany will have
67 as much money as Roshel. How much money does Roshel have?
| |
Case 1 |
Case 2 |
| |
Tiffany |
Roshel |
Tiffany |
Roshel |
| Before |
2 u + $20 |
5 u |
6 p |
7 p + $6 |
| Change |
- $20 |
|
|
- $6 |
| After |
2 u |
5 u |
6 p |
7 p |
The amount that Tiffany has at first in Case 1 and Case 2 is the same.
2 u + 20 = 6 p
2 u = 6 p - 20 --- (1)
The amount that Roshel has at first in Case 1 and Case 2 is the same.
5 u = 7 p + 6 --- (2)
Make u the same.
(1)
x 510 u = 30 p - 100 --- (3)
(2)
x 210 u = 14 p + 12 --- (4)
(3) = (4)
30 p - 100 = 14 p + 12
30 p - 14 p = 100 + 12
16 p = 112
1 p = 112 ÷ 16 = 7
Amount that Roshel has
= 7 p + 6
= 7 x 7 + 6
= 49 + 6
= $55
Answer(s): $55
