Gillian and Erika had $89. Erika had $1 more than Gillian. Gillian spent 3 times as much as Erika and was left with
23 as much as Erika. How much did Gillian spend more than Erika?
| |
Make p the same
(1)x3 = (3) |
Gillian
(1) |
Erika
(2) |
Make p the same
(2)x2 = (4) |
Total
|
Comparing Gillian
and Erika at first |
|
|
$1 more |
|
$89 |
| Before |
$132 |
$44 |
$45 |
$90 |
|
| Change |
- 9 u |
- 3 u |
- 1 u |
- 2 u |
|
| After |
6 p |
2 p |
3 p |
6 p |
|
Amount that Gillian had at first
= (89 - 1) ÷ 2
= 88 ÷ 2
= $44
Amount that Erika had at first
= 44 + 1
= $45
44 - 3 u = 2 p --- (1)
45 - 1 u = 3 p --- (2)
Make p the same.
(1)
x 3
132 - 9 u =
6 p --- (3)
(2)
x 2
90 - 2 u =
6 p --- (4)
(4) = (3)
90 - 2 u = 132 - 9 u
9 u - 2 u = 132 - 90
7 u = 42
1 u = 42 ÷ 7 = 6
Amount that Gillian spent more than Erika
= 3 u - 1 u
= 2 u
= 2 x 6
= $12
Answer(s): $12
