Kathy and Julie had $121. Julie had $29 more than Kathy. Kathy spent 2 times as much as Julie and was left with
25 as much as Julie. How much did Kathy spend?
| |
Make p the same
(1)x5 = (3) |
Kathy
(1) |
Julie
(2) |
Make p the same
(2)x2 = (4) |
Total
|
Comparing Kathy
and Julie at first |
|
|
$29 more |
|
$121 |
| Before |
$230 |
$46 |
$75 |
$150 |
|
| Change |
- 10 u |
- 2 u |
- 1 u |
- 2 u |
|
| After |
10 p |
2 p |
5 p |
10 p |
|
Amount that Kathy had at first
= (121 - 29) ÷ 2
= 92 ÷ 2
= $46
Amount that Julie had at first
= 46 + 29
= $75
46 - 2 u = 2 p --- (1)
75 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
230 - 10 u =
10 p --- (3)
(2)
x 2
150 - 2 u =
10 p --- (4)
(4) = (3)
150 - 2 u = 230 - 10 u
10 u - 2 u = 230 - 150
8 u = 80
1 u = 80 ÷ 8 = 10
Amount that Kathy spent
= 2 u
= 2 x 10
= $20
Answer(s): $20
