Anna and Xandra had $140. Xandra had $8 more than Anna. Anna spent 3 times as much as Xandra and was left with
35 as much as Xandra. How much did Xandra spend less than Anna?
| |
Make p the same
(1) x 5 = (3) |
Anna
(1) |
Xandra
(2) |
Make p the same
(2) x 3 = (4) |
Total
|
Comparing Anna
and Xandra at first |
|
|
$8 more |
|
$140 |
| Before |
$330 |
$66 |
$74 |
$222 |
|
| Change |
- 15 u |
- 3 u |
- 1 u |
- 3 u |
|
| After |
15 p |
3 p |
5 p |
15 p |
|
Amount that Anna had at first
= (140 - 8) ÷ 2
= 132 ÷ 2
= $66
Amount that Xandra had at first
= 66 + 8
= $74
66 - 3 u = 3 p --- (1)
74 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
330 - 15 u =
15 p --- (3)
(2)
x 3
222 - 3 u =
15 p --- (4)
(4) = (3)
222 - 3 u = 330 - 15 u
15 u - 3 u = 330 - 222
12 u = 108
1 u = 108 ÷ 12 = 9
Amount that Xandra spent less than Anna
= 3 u - 1 u
= 2 u
= 2 x 9
= $18
Answer(s): $18
