Three girls, Usha, Xuan and Kimberly had a total of 3780 stickers. Some exchanges were made. First, Usha gave Xuan as many stickers as Xuan had. After that, Xuan gave
13 of whatever she had then to Kimberly. Finally, Kimberly gave
13 of whatever she had to Usha. As a result, they each had the same number of stickers. How many stickers did Usha have at first?
|
Usha |
Xuan |
Kimberly |
Total |
Before 1 |
? |
1 u |
|
3780 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
3 p |
|
3780 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
2 p |
|
|
Before 3 |
|
|
3 boxes |
3780 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
2 boxes |
|
After 3 |
1 group |
1 group |
1 group |
3780 |
3 groups = 3780
1 group = 3780 ÷ 3 = 1260
1 group = 2 boxes 2 boxes = 1260
1 box = 1260 ÷ 2 = 630
2 p = 1 group
1 p = 1260 ÷ 2 = 630
3 p = 3 x 630 = 1890
3 p = 2 u
2 u = 1890
1 u = 1890 ÷ 2 = 945
Number of stickers that Usha had at first
= 1 group - 1 box + 1 u
= 1260 - 630 + 945
= 1575
Answer(s): 1575