Abi and Ivory had $115. Ivory had $9 more than Abi. Abi spent 3 times as much as Ivory and was left with
23 as much as Ivory. How much did Ivory spend less than Abi?
| |
Make p the same
(1) x 3 = (3) |
Abi
(1) |
Ivory
(2) |
Make p the same
(2) x 2 = (4) |
Total
|
Comparing Abi
and Ivory at first |
|
|
$9 more |
|
$115 |
| Before |
$159 |
$53 |
$62 |
$124 |
|
| Change |
- 9 u |
- 3 u |
- 1 u |
- 2 u |
|
| After |
6 p |
2 p |
3 p |
6 p |
|
Amount that Abi had at first
= (115 - 9) ÷ 2
= 106 ÷ 2
= $53
Amount that Ivory had at first
= 53 + 9
= $62
53 - 3 u = 2 p --- (1)
62 - 1 u = 3 p --- (2)
Make p the same.
(1)
x 3
159 - 9 u =
6 p --- (3)
(2)
x 2
124 - 2 u =
6 p --- (4)
(4) = (3)
124 - 2 u = 159 - 9 u
9 u - 2 u = 159 - 124
7 u = 35
1 u = 35 ÷ 7 = 5
Amount that Ivory spent less than Abi
= 3 u - 1 u
= 2 u
= 2 x 5
= $10
Answer(s): $10
