Three girls, Dana, Gwen and Gillian had a total of 1020 stickers. Some exchanges were made. First, Dana gave Gwen as many stickers as Gwen had. After that, Gwen gave
13 of whatever she had then to Gillian. Finally, Gillian gave
15 of whatever she had to Dana. As a result, they each had the same number of stickers. How many stickers did Dana have at first?
|
Dana |
Gwen |
Gillian |
Total |
Before 1 |
? |
1 u |
|
1020 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
3 p |
|
1020 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
2 p |
|
|
Before 3 |
|
|
5 boxes |
1020 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
4 boxes |
|
After 3 |
1 group |
1 group |
1 group |
1020 |
3 groups = 1020
1 group = 1020 ÷ 3 = 340
1 group = 4 boxes 4 boxes = 340
1 box = 340 ÷ 4 = 85
2 p = 1 group
1 p = 340 ÷ 2 = 170
3 p = 3 x 170 = 510
3 p = 2 u
2 u = 510
1 u = 510 ÷ 2 = 255
Number of stickers that Dana had at first
= 1 group - 1 box + 1 u
= 340 - 85 + 255
= 510
Answer(s): 510