Barbara and Wendy have some money. If Barbara spends $4, she will have
25 as much money as Wendy. If Wendy spends $8, Barbara will have
47 as much money as Wendy. How much money does Wendy have?
| |
Case 1 |
Case 2 |
| |
Barbara |
Wendy |
Barbara |
Wendy |
| Before |
2 u + $4 |
5 u |
4 p |
7 p + $8 |
| Change |
- $4 |
|
|
- $8 |
| After |
2 u |
5 u |
4 p |
7 p |
The amount that Barbara has at first in Case 1 and Case 2 is the same.
2 u + 4 = 4 p
2 u = 4 p - 4 --- (1)
The amount that Wendy has at first in Case 1 and Case 2 is the same.
5 u = 7 p + 8 --- (2)
Make u the same.
(1)
x 510 u = 20 p - 20 --- (3)
(2)
x 210 u = 14 p + 16 --- (4)
(3) = (4)
20 p - 20 = 14 p + 16
20 p - 14 p = 20 + 16
6 p = 36
1 p = 36 ÷ 6 = 6
Amount that Wendy has
= 7 p + 8
= 7 x 6 + 8
= 42 + 8
= $50
Answer(s): $50
