Eva and Min have some money. If Eva spends $2, she will have
25 as much money as Min. If Min spends $11, Eva will have
67 as much money as Min. How much money does Eva have?
| |
Case 1 |
Case 2 |
| |
Eva |
Min |
Eva |
Min |
| Before |
2 u + $2 |
5 u |
6 p |
7 p + $11 |
| Change |
- $2 |
|
|
- $11 |
| After |
2 u |
5 u |
6 p |
7 p |
The amount that Eva has at first in Case 1 and Case 2 is the same.
2 u + 2 = 6 p
2 u = 6 p - 2 --- (1)
The amount that Min 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 - 10 --- (3)
(2)
x 210 u = 14 p + 22 --- (4)
(3) = (4)
30 p - 10 = 14 p + 22
30 p - 14 p = 10 + 22
16 p = 32
1 p = 32 ÷ 16 = 2
Amount that Eva has
= 6 p
= 6 x 2
= $12
Answer(s): $12
