Cindy and Abi had $124. Abi had $16 more than Cindy. Cindy spent 3 times as much as Abi and was left with
35 as much as Abi. How much did Cindy spend?
| |
Make p the same
(1)x5 = (3) |
Cindy
(1) |
Abi
(2) |
Make p the same
(2)x3 = (4) |
Total
|
Comparing Cindy
and Abi at first |
|
|
$16 more |
|
$124 |
| Before |
$270 |
$54 |
$70 |
$210 |
|
| Change |
- 15 u |
- 3 u |
- 1 u |
- 3 u |
|
| After |
15 p |
3 p |
5 p |
15 p |
|
Amount that Cindy had at first
= (124 - 16) ÷ 2
= 108 ÷ 2
= $54
Amount that Abi had at first
= 54 + 16
= $70
54 - 3 u = 3 p --- (1)
70 - 1 u = 5 p --- (2)
Make p the same.
(1)
x 5
270 - 15 u =
15 p --- (3)
(2)
x 3
210 - 3 u =
15 p --- (4)
(4) = (3)
210 - 3 u = 270 - 15 u
15 u - 3 u = 270 - 210
12 u = 60
1 u = 60 ÷ 12 = 5
Amount that Cindy spent
= 3 u
= 3 x 5
= $15
Answer(s): $15
