Emily and Abi had $99. Abi had $3 more than Emily. Emily spent 3 times as much as Abi and was left with
23 as much as Abi. How much did Emily spend?
| |
Make p the same
(1)x3 = (3) |
Emily
(1) |
Abi
(2) |
Make p the same
(2)x2 = (4) |
Total
|
Comparing Emily
and Abi at first |
|
|
$3 more |
|
$99 |
| Before |
$144 |
$48 |
$51 |
$102 |
|
| Change |
- 9 u |
- 3 u |
- 1 u |
- 2 u |
|
| After |
6 p |
2 p |
3 p |
6 p |
|
Amount that Emily had at first
= (99 - 3) ÷ 2
= 96 ÷ 2
= $48
Amount that Abi had at first
= 48 + 3
= $51
48 - 3 u = 2 p --- (1)
51 - 1 u = 3 p --- (2)
Make p the same.
(1)
x 3
144 - 9 u =
6 p --- (3)
(2)
x 2
102 - 2 u =
6 p --- (4)
(4) = (3)
102 - 2 u = 144 - 9 u
9 u - 2 u = 144 - 102
7 u = 42
1 u = 42 ÷ 7 = 6
Amount that Emily spent
= 3 u
= 3 x 6
= $18
Answer(s): $18
