Gillian and Zara have some money. If Gillian spends $5, she will have
34 as much money as Zara. If Zara spends $4, Gillian will have
78 as much money as Zara. How much money does Gillian have?
| |
Case 1 |
Case 2 |
| |
Gillian |
Zara |
Gillian |
Zara |
| Before |
3 u + $5 |
4 u |
7 p |
8 p + $4 |
| Change |
- $5 |
|
|
- $4 |
| After |
3 u |
4 u |
7 p |
8 p |
The amount that Gillian has at first in Case 1 and Case 2 is the same.
3 u + 5 = 7 p
3 u = 7 p - 5 --- (1)
The amount that Zara has at first in Case 1 and Case 2 is the same.
4 u = 8 p + 4 --- (2)
Make u the same.
(1)
x 412 u = 28 p - 20 --- (3)
(2)
x 312 u = 24 p + 12 --- (4)
(3) = (4)
28 p - 20 = 24 p + 12
28 p - 24 p = 20 + 12
4 p = 32
1 p = 32 ÷ 4 = 8
Amount that Gillian has
= 7 p
= 7 x 8
= $56
Answer(s): $56
