Penelope and Min had $108. Min had $4 more than Penelope. Penelope spent 2 times as much as Min and was left with
23 as much as Min. How much did Penelope spend?
| |
Make p the same
(1)x3 = (3) |
Penelope
(1) |
Min
(2) |
Make p the same
(2)x2 = (4) |
Total
|
Comparing Penelope
and Min at first |
|
|
$4 more |
|
$108 |
| Before |
$156 |
$52 |
$56 |
$112 |
|
| Change |
- 6 u |
- 2 u |
- 1 u |
- 2 u |
|
| After |
6 p |
2 p |
3 p |
6 p |
|
Amount that Penelope had at first
= (108 - 4) ÷ 2
= 104 ÷ 2
= $52
Amount that Min had at first
= 52 + 4
= $56
52 - 2 u = 2 p --- (1)
56 - 1 u = 3 p --- (2)
Make p the same.
(1)
x 3
156 - 6 u =
6 p --- (3)
(2)
x 2
112 - 2 u =
6 p --- (4)
(4) = (3)
112 - 2 u = 156 - 6 u
6 u - 2 u = 156 - 112
4 u = 44
1 u = 44 ÷ 4 = 11
Amount that Penelope spent
= 2 u
= 2 x 11
= $22
Answer(s): $22
