Risa and Min had $199. Min had $3 more than Risa. Risa spent 4 times as much as Min and was left with
35 as much as Min. How much did Min spend less than Risa?
| |
Make p the same
(1) x 5 = (3) |
Risa
(1) |
Min
(2) |
Make p the same
(2) x 3 = (4) |
Total
|
Comparing Risa
and Min at first |
|
|
$3 more |
|
$199 |
| Before |
$490 |
$98 |
$101 |
$303 |
|
| Change |
- 20 u |
- 4 u |
- 1 u |
- 3 u |
|
| After |
15 p |
3 p |
5 p |
15 p |
|
Amount that Risa had at first
= (199 - 3) ÷ 2
= 196 ÷ 2
= $98
Amount that Min had at first
= 98 + 3
= $101
98 - 4 u = 3 p --- (1)
101 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
490 - 20 u =
15 p --- (3)
(2)
x 3
303 - 3 u =
15 p --- (4)
(4) = (3)
303 - 3 u = 490 - 20 u
20 u - 3 u = 490 - 303
17 u = 187
1 u = 187 ÷ 17 = 11
Amount that Min spent less than Risa
= 4 u - 1 u
= 3 u
= 3 x 11
= $33
Answer(s): $33
