Shiyun and Eva have some money. If Shiyun spends $15, she will have
35 as much money as Eva. If Eva spends $8, Shiyun will have
67 as much money as Eva. How much money does Shiyun have?
| |
Case 1 |
Case 2 |
| |
Shiyun |
Eva |
Shiyun |
Eva |
| Before |
3 u + $15 |
5 u |
6 p |
7 p + $8 |
| Change |
- $15 |
|
|
- $8 |
| After |
3 u |
5 u |
6 p |
7 p |
The amount that Shiyun has at first in Case 1 and Case 2 is the same.
3 u + 15 = 6 p
3 u = 6 p - 15 --- (1)
The amount that Eva has at first in Case 1 and Case 2 is the same.
5 u = 7 p + 8 --- (2)
Make u the same.
(1)
x 515 u = 30 p - 75 --- (3)
(2)
x 315 u = 21 p + 24 --- (4)
(3) = (4)
30 p - 75 = 21 p + 24
30 p - 21 p = 75 + 24
9 p = 99
1 p = 99 ÷ 9 = 11
Amount that Shiyun has
= 6 p
= 6 x 11
= $66
Answer(s): $66
