Xandra and Risa have some money. If Xandra spends $34, she will have
25 as much money as Risa. If Risa spends $11, Xandra will have
67 as much money as Risa. How much money does Xandra have?
| |
Case 1 |
Case 2 |
| |
Xandra |
Risa |
Xandra |
Risa |
| Before |
2 u + $34 |
5 u |
6 p |
7 p + $11 |
| Change |
- $34 |
|
|
- $11 |
| After |
2 u |
5 u |
6 p |
7 p |
The amount that Xandra has at first in Case 1 and Case 2 is the same.
2 u + 34 = 6 p
2 u = 6 p - 34 --- (1)
The amount that Risa has at first in Case 1 and Case 2 is the same.
5 u = 7 p + 11 --- (2)
Make u the same.
(1)
x 510 u = 30 p - 170 --- (3)
(2)
x 210 u = 14 p + 22 --- (4)
(3) = (4)
30 p - 170 = 14 p + 22
30 p - 14 p = 170 + 22
16 p = 192
1 p = 192 ÷ 16 = 12
Amount that Xandra has
= 6 p
= 6 x 12
= $72
Answer(s): $72
