Elyse and Betty had $185. Betty had $25 more than Elyse. Elyse spent 4 times as much as Betty and was left with
35 as much as Betty. How much did Elyse spend?
| |
Make p the same
(1)x5 = (3) |
Elyse
(1) |
Betty
(2) |
Make p the same
(2)x3 = (4) |
Total
|
Comparing Elyse
and Betty at first |
|
|
$25 more |
|
$185 |
| Before |
$400 |
$80 |
$105 |
$315 |
|
| Change |
- 20 u |
- 4 u |
- 1 u |
- 3 u |
|
| After |
15 p |
3 p |
5 p |
15 p |
|
Amount that Elyse had at first
= (185 - 25) ÷ 2
= 160 ÷ 2
= $80
Amount that Betty had at first
= 80 + 25
= $105
80 - 4 u = 3 p --- (1)
105 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
400 - 20 u =
15 p --- (3)
(2)
x 3
315 - 3 u =
15 p --- (4)
(4) = (3)
315 - 3 u = 400 - 20 u
20 u - 3 u = 400 - 315
17 u = 85
1 u = 85 ÷ 17 = 5
Amount that Elyse spent
= 4 u
= 4 x 5
= $20
Answer(s): $20
