Jaslyn and Jane have some money. If Jaslyn spends $20, she will have
25 as much money as Jane. If Jane spends $7, Jaslyn will have
78 as much money as Jane. How much money does Jaslyn have?
| |
Case 1 |
Case 2 |
| |
Jaslyn |
Jane |
Jaslyn |
Jane |
| Before |
2 u + $20 |
5 u |
7 p |
8 p + $7 |
| Change |
- $20 |
|
|
- $7 |
| After |
2 u |
5 u |
7 p |
8 p |
The amount that Jaslyn has at first in Case 1 and Case 2 is the same.
2 u + 20 = 7 p
2 u = 7 p - 20 --- (1)
The amount that Jane has at first in Case 1 and Case 2 is the same.
5 u = 8 p + 7 --- (2)
Make u the same.
(1)
x 510 u = 35 p - 100 --- (3)
(2)
x 210 u = 16 p + 14 --- (4)
(3) = (4)
35 p - 100 = 16 p + 14
35 p - 16 p = 100 + 14
19 p = 114
1 p = 114 ÷ 19 = 6
Amount that Jaslyn has
= 7 p
= 7 x 6
= $42
Answer(s): $42
