Irene and Gabby had $171. Gabby had $13 more than Irene. Irene spent 4 times as much as Gabby and was left with
35 as much as Gabby. How much did Irene spend more than Gabby?
| |
Make p the same
(1)x5 = (3) |
Irene
(1) |
Gabby
(2) |
Make p the same
(2)x3 = (4) |
Total
|
Comparing Irene
and Gabby at first |
|
|
$13 more |
|
$171 |
| Before |
$395 |
$79 |
$92 |
$276 |
|
| Change |
- 20 u |
- 4 u |
- 1 u |
- 3 u |
|
| After |
15 p |
3 p |
5 p |
15 p |
|
Amount that Irene had at first
= (171 - 13) ÷ 2
= 158 ÷ 2
= $79
Amount that Gabby had at first
= 79 + 13
= $92
79 - 4 u = 3 p --- (1)
92 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
395 - 20 u =
15 p --- (3)
(2)
x 3
276 - 3 u =
15 p --- (4)
(4) = (3)
276 - 3 u = 395 - 20 u
20 u - 3 u = 395 - 276
17 u = 119
1 u = 119 ÷ 17 = 7
Amount that Irene spent more than Gabby
= 4 u - 1 u
= 3 u
= 3 x 7
= $21
Answer(s): $21
