Erika and Wendy had $125. Wendy had $35 more than Erika. Erika spent 3 times as much as Wendy and was left with
25 as much as Wendy. How much did Erika spend more than Wendy?
| |
Make p the same
(1)x5 = (3) |
Erika
(1) |
Wendy
(2) |
Make p the same
(2)x2 = (4) |
Total
|
Comparing Erika
and Wendy at first |
|
|
$35 more |
|
$125 |
| Before |
$225 |
$45 |
$80 |
$160 |
|
| Change |
- 15 u |
- 3 u |
- 1 u |
- 2 u |
|
| After |
10 p |
2 p |
5 p |
10 p |
|
Amount that Erika had at first
= (125 - 35) ÷ 2
= 90 ÷ 2
= $45
Amount that Wendy had at first
= 45 + 35
= $80
45 - 3 u = 2 p --- (1)
80 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
225 - 15 u =
10 p --- (3)
(2)
x 2
160 - 2 u =
10 p --- (4)
(4) = (3)
160 - 2 u = 225 - 15 u
15 u - 2 u = 225 - 160
13 u = 65
1 u = 65 ÷ 13 = 5
Amount that Erika spent more than Wendy
= 3 u - 1 u
= 2 u
= 2 x 5
= $10
Answer(s): $10
