Three girls, Kathy, Tiffany and Barbara had a total of 2820 stickers. Some exchanges were made. First, Kathy gave Tiffany as many stickers as Tiffany had. After that, Tiffany gave
13 of whatever she had then to Barbara. Finally, Barbara gave
13 of whatever she had to Kathy. As a result, they each had the same number of stickers. How many stickers did Kathy have at first?
|
Kathy |
Tiffany |
Barbara |
Total |
Before 1 |
? |
1 u |
|
2820 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
3 p |
|
2820 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
2 p |
|
|
Before 3 |
|
|
3 boxes |
2820 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
2 boxes |
|
After 3 |
1 group |
1 group |
1 group |
2820 |
3 groups = 2820
1 group = 2820 ÷ 3 = 940
1 group = 2 boxes 2 boxes = 940
1 box = 940 ÷ 2 = 470
2 p = 1 group
1 p = 940 ÷ 2 = 470
3 p = 3 x 470 = 1410
3 p = 2 u
2 u = 1410
1 u = 1410 ÷ 2 = 705
Number of stickers that Kathy had at first
= 1 group - 1 box + 1 u
= 940 - 470 + 705
= 1175
Answer(s): 1175