Penelope and Jen had $210. Jen had $10 more than Penelope. Penelope spent 4 times as much as Jen and was left with
35 as much as Jen. How much did Jen spend less than Penelope?
| |
Make p the same
(1) x 5 = (3) |
Penelope
(1) |
Jen
(2) |
Make p the same
(2) x 3 = (4) |
Total
|
Comparing Penelope
and Jen at first |
|
|
$10 more |
|
$210 |
| Before |
$500 |
$100 |
$110 |
$330 |
|
| Change |
- 20 u |
- 4 u |
- 1 u |
- 3 u |
|
| After |
15 p |
3 p |
5 p |
15 p |
|
Amount that Penelope had at first
= (210 - 10) ÷ 2
= 200 ÷ 2
= $100
Amount that Jen had at first
= 100 + 10
= $110
100 - 4 u = 3 p --- (1)
110 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
500 - 20 u =
15 p --- (3)
(2)
x 3
330 - 3 u =
15 p --- (4)
(4) = (3)
330 - 3 u = 500 - 20 u
20 u - 3 u = 500 - 330
17 u = 170
1 u = 170 ÷ 17 = 10
Amount that Jen spent less than Penelope
= 4 u - 1 u
= 3 u
= 3 x 10
= $30
Answer(s): $30
