Three girls, Winnie, Penelope and Jaslyn had a total of 1800 pens. Some exchanges were made. First, Winnie gave Penelope as many pens as Penelope had. After that, Penelope gave
15 of whatever she had then to Jaslyn. Finally, Jaslyn gave
13 of whatever she had to Winnie. As a result, they each had the same number of pens. How many pens did Winnie have at first?
|
Winnie |
Penelope |
Jaslyn |
Total |
Before 1 |
? |
1 u |
|
1800 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
5 p |
|
1800 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
4 p |
|
|
Before 3 |
|
|
3 boxes |
1800 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
2 boxes |
|
After 3 |
1 group |
1 group |
1 group |
1800 |
3 groups = 1800
1 group = 1800 ÷ 3 = 600
1 group = 2 boxes 2 boxes = 600
1 box = 600 ÷ 2 = 300
4 p = 1 group
1 p = 600 ÷ 4 = 150
5 p = 5 x 150 = 750
5 p = 2 u
2 u = 750
1 u = 750 ÷ 2 = 375
Number of pens that Winnie had at first
= 1 group - 1 box + 1 u
= 600 - 300 + 375
= 675
Answer(s): 675