Min and Diana had $165. Diana had $45 more than Min. Min spent 4 times as much as Diana and was left with
25 as much as Diana. How much did Min spend?
| |
Make p the same
(1)x5 = (3) |
Min
(1) |
Diana
(2) |
Make p the same
(2)x2 = (4) |
Total
|
Comparing Min
and Diana at first |
|
|
$45 more |
|
$165 |
| Before |
$300 |
$60 |
$105 |
$210 |
|
| Change |
- 20 u |
- 4 u |
- 1 u |
- 2 u |
|
| After |
10 p |
2 p |
5 p |
10 p |
|
Amount that Min had at first
= (165 - 45) ÷ 2
= 120 ÷ 2
= $60
Amount that Diana had at first
= 60 + 45
= $105
60 - 4 u = 2 p --- (1)
105 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
300 - 20 u =
10 p --- (3)
(2)
x 2
210 - 2 u =
10 p --- (4)
(4) = (3)
210 - 2 u = 300 - 20 u
20 u - 2 u = 300 - 210
18 u = 90
1 u = 90 ÷ 18 = 5
Amount that Min spent
= 4 u
= 4 x 5
= $20
Answer(s): $20
