Cindy and Cathy had $71 at first. Cindy spent
47 of her money and Cathy spent
23 of her money. Given that they had $57 left, how much did Cindy have at first?
| |
Cindy |
Cathy |
Total |
| Before |
7 u |
3 p |
$71 |
| Change |
- 4 u |
- 2 p |
|
| After |
3 u |
1 p |
$57 |
7 u + 3 p = 71 --- (1)
3 u + 1 p = 57 --- (2)
(2) x 3 9 u + 3 p = 171 --- (3)
(3) - (1)
9 u - 7 u = 171 - 71
2 u = 100
1 u = 100 ÷ 2 = 50
Amount that Cindy had at first
= 7 u
= 7 x 50
= $350
Answer(s): $350
