Jen and Barbara had $148. Barbara had $30 more than Jen. Jen spent 3 times as much as Barbara and was left with
25 as much as Barbara. How much did Barbara spend less than Jen?
| |
Make p the same
(1) x 5 = (3) |
Jen
(1) |
Barbara
(2) |
Make p the same
(2) x 2 = (4) |
Total
|
Comparing Jen
and Barbara at first |
|
|
$30 more |
|
$148 |
| Before |
$295 |
$59 |
$89 |
$178 |
|
| Change |
- 15 u |
- 3 u |
- 1 u |
- 2 u |
|
| After |
10 p |
2 p |
5 p |
10 p |
|
Amount that Jen had at first
= (148 - 30) ÷ 2
= 118 ÷ 2
= $59
Amount that Barbara had at first
= 59 + 30
= $89
59 - 3 u = 2 p --- (1)
89 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
295 - 15 u =
10 p --- (3)
(2)
x 2
178 - 2 u =
10 p --- (4)
(4) = (3)
178 - 2 u = 295 - 15 u
15 u - 2 u = 295 - 178
13 u = 117
1 u = 117 ÷ 13 = 9
Amount that Barbara spent less than Jen
= 3 u - 1 u
= 2 u
= 2 x 9
= $18
Answer(s): $18
