Kylie and Betty had $215. Betty had $7 more than Kylie. Kylie spent 4 times as much as Betty and was left with
35 as much as Betty. How much did Betty spend less than Kylie?
| |
Make p the same
(1) x 5 = (3) |
Kylie
(1) |
Betty
(2) |
Make p the same
(2) x 3 = (4) |
Total
|
Comparing Kylie
and Betty at first |
|
|
$7 more |
|
$215 |
| Before |
$520 |
$104 |
$111 |
$333 |
|
| Change |
- 20 u |
- 4 u |
- 1 u |
- 3 u |
|
| After |
15 p |
3 p |
5 p |
15 p |
|
Amount that Kylie had at first
= (215 - 7) ÷ 2
= 208 ÷ 2
= $104
Amount that Betty had at first
= 104 + 7
= $111
104 - 4 u = 3 p --- (1)
111 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
520 - 20 u =
15 p --- (3)
(2)
x 3
333 - 3 u =
15 p --- (4)
(4) = (3)
333 - 3 u = 520 - 20 u
20 u - 3 u = 520 - 333
17 u = 187
1 u = 187 ÷ 17 = 11
Amount that Betty spent less than Kylie
= 4 u - 1 u
= 3 u
= 3 x 11
= $33
Answer(s): $33
