Three girls, Gabby, Penelope and Shiyun had a total of 4950 pens. Some exchanges were made. First, Gabby gave Penelope as many pens as Penelope had. After that, Penelope gave
14 of whatever she had then to Shiyun. Finally, Shiyun gave
14 of whatever she had to Gabby. As a result, they each had the same number of pens. How many pens did Gabby have at first?
|
Gabby |
Penelope |
Shiyun |
Total |
Before 1 |
? |
1 u |
|
4950 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
4 p |
|
4950 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
3 p |
|
|
Before 3 |
|
|
4 boxes |
4950 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
3 boxes |
|
After 3 |
1 group |
1 group |
1 group |
4950 |
3 groups = 4950
1 group = 4950 ÷ 3 = 1650
1 group = 3 boxes 3 boxes = 1650
1 box = 1650 ÷ 3 = 550
3 p = 1 group
1 p = 1650 ÷ 3 = 550
4 p = 4 x 550 = 2200
4 p = 2 u
2 u = 2200
1 u = 2200 ÷ 2 = 1100
Number of pens that Gabby had at first
= 1 group - 1 box + 1 u
= 1650 - 550 + 1100
= 2200
Answer(s): 2200