Betty and Linda had $193. Linda had $21 more than Betty. Betty spent 4 times as much as Linda and was left with
25 as much as Linda. How much did Betty spend more than Linda?
| |
Make p the same
(1)x5 = (3) |
Betty
(1) |
Linda
(2) |
Make p the same
(2)x2 = (4) |
Total
|
Comparing Betty
and Linda at first |
|
|
$21 more |
|
$193 |
| Before |
$430 |
$86 |
$107 |
$214 |
|
| Change |
- 20 u |
- 4 u |
- 1 u |
- 2 u |
|
| After |
10 p |
2 p |
5 p |
10 p |
|
Amount that Betty had at first
= (193 - 21) ÷ 2
= 172 ÷ 2
= $86
Amount that Linda had at first
= 86 + 21
= $107
86 - 4 u = 2 p --- (1)
107 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
430 - 20 u =
10 p --- (3)
(2)
x 2
214 - 2 u =
10 p --- (4)
(4) = (3)
214 - 2 u = 430 - 20 u
20 u - 2 u = 430 - 214
18 u = 216
1 u = 216 ÷ 18 = 12
Amount that Betty spent more than Linda
= 4 u - 1 u
= 3 u
= 3 x 12
= $36
Answer(s): $36
