Barbara and Gabby had $158. Gabby had $6 more than Barbara. Barbara spent 4 times as much as Gabby and was left with
25 as much as Gabby. How much did Gabby spend less than Barbara?
| |
Make p the same
(1) x 5 = (3) |
Barbara
(1) |
Gabby
(2) |
Make p the same
(2) x 2 = (4) |
Total
|
Comparing Barbara
and Gabby at first |
|
|
$6 more |
|
$158 |
| Before |
$380 |
$76 |
$82 |
$164 |
|
| Change |
- 20 u |
- 4 u |
- 1 u |
- 2 u |
|
| After |
10 p |
2 p |
5 p |
10 p |
|
Amount that Barbara had at first
= (158 - 6) ÷ 2
= 152 ÷ 2
= $76
Amount that Gabby had at first
= 76 + 6
= $82
76 - 4 u = 2 p --- (1)
82 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
380 - 20 u =
10 p --- (3)
(2)
x 2
164 - 2 u =
10 p --- (4)
(4) = (3)
164 - 2 u = 380 - 20 u
20 u - 2 u = 380 - 164
18 u = 216
1 u = 216 ÷ 18 = 12
Amount that Gabby spent less than Barbara
= 4 u - 1 u
= 3 u
= 3 x 12
= $36
Answer(s): $36
