Three girls, Olivia, Julie and Yoko had a total of 3720 stamps. Some exchanges were made. First, Olivia gave Julie as many stamps as Julie had. After that, Julie gave
13 of whatever she had then to Yoko. Finally, Yoko gave
15 of whatever she had to Olivia. As a result, they each had the same number of stamps. How many stamps did Olivia have at first?
|
Olivia |
Julie |
Yoko |
Total |
Before 1 |
? |
1 u |
|
3720 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
3 p |
|
3720 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
2 p |
|
|
Before 3 |
|
|
5 boxes |
3720 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
4 boxes |
|
After 3 |
1 group |
1 group |
1 group |
3720 |
3 groups = 3720
1 group = 3720 ÷ 3 = 1240
1 group = 4 boxes 4 boxes = 1240
1 box = 1240 ÷ 4 = 310
2 p = 1 group
1 p = 1240 ÷ 2 = 620
3 p = 3 x 620 = 1860
3 p = 2 u
2 u = 1860
1 u = 1860 ÷ 2 = 930
Number of stamps that Olivia had at first
= 1 group - 1 box + 1 u
= 1240 - 310 + 930
= 1860
Answer(s): 1860