Mary had $300 more than Cindy. Mary gave
23 of her money to Cindy. Cindy then gave 20% of her money to Mary. In the end, Cindy had $208 more than Mary. How much did Mary have at first?
| |
Mary |
Cindy |
Comparing Mary
and Cindy at first |
300 more |
|
| Before |
3 u |
+ 300 |
3 u |
|
| Change 1 |
- 2 u |
- 200 |
+ 2 u |
+ 200 |
| After 1 |
1 u |
+ 100 |
5 u |
+ 200 |
| Change 2 |
+ 1 u |
+ 40 |
- 1 u |
- 40 |
| After 2 |
2 u |
+ 140 |
4 u |
+ 160 |
23 x 300= 200
300 - 200 = 100
20% x 5 u
=
20100 x 5 u
= 1 u
20% x 200
=
20100 x 200
= 40
200 - 40 = 160
100 + 40 = 140
If Mary received another $208 in the end, Mary and Cindy would have the same amount of money.
4 u + 160 = 2 u + 140 + 208
4 u - 2 u = 140 + 208 - 160
2 u = 188
1 u = 188 ÷ 2 = 94
Amount that Mary had at first
= 3 u + 300
= 3 x 94 + 300
= 282 + 300
= $582
Answer(s): $582
