Nora and Yen have some money. If Nora spends $2, she will have
25 as much money as Yen. If Yen spends $28, Nora will have
57 as much money as Yen. How much money does Nora have?
| |
Case 1 |
Case 2 |
| |
Nora |
Yen |
Nora |
Yen |
| Before |
2 u + $2 |
5 u |
5 p |
7 p + $28 |
| Change |
- $2 |
|
|
- $28 |
| After |
2 u |
5 u |
5 p |
7 p |
The amount that Nora has at first in Case 1 and Case 2 is the same.
2 u + 2 = 5 p
2 u = 5 p - 2 --- (1)
The amount that Yen has at first in Case 1 and Case 2 is the same.
5 u = 7 p + 28 --- (2)
Make u the same.
(1)
x 510 u = 25 p - 10 --- (3)
(2)
x 210 u = 14 p + 56 --- (4)
(3) = (4)
25 p - 10 = 14 p + 56
25 p - 14 p = 10 + 56
11 p = 66
1 p = 66 ÷ 11 = 6
Amount that Nora has
= 5 p
= 5 x 6
= $30
Answer(s): $30
