Three girls, Winnie, Jean and Cindy had a total of 2220 stamps. Some exchanges were made. First, Winnie gave Jean as many stamps as Jean had. After that, Jean gave
13 of whatever she had then to Cindy. Finally, Cindy gave
13 of whatever she had to Winnie. As a result, they each had the same number of stamps. How many stamps did Winnie have at first?
|
Winnie |
Jean |
Cindy |
Total |
Before 1 |
? |
1 u |
|
2220 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
3 p |
|
2220 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
2 p |
|
|
Before 3 |
|
|
3 boxes |
2220 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
2 boxes |
|
After 3 |
1 group |
1 group |
1 group |
2220 |
3 groups = 2220
1 group = 2220 ÷ 3 = 740
1 group = 2 boxes 2 boxes = 740
1 box = 740 ÷ 2 = 370
2 p = 1 group
1 p = 740 ÷ 2 = 370
3 p = 3 x 370 = 1110
3 p = 2 u
2 u = 1110
1 u = 1110 ÷ 2 = 555
Number of stamps that Winnie had at first
= 1 group - 1 box + 1 u
= 740 - 370 + 555
= 925
Answer(s): 925