Three girls, Zoe, Pamela and Eva had a total of 900 erasers. Some exchanges were made. First, Zoe gave Pamela as many erasers as Pamela had. After that, Pamela gave
13 of whatever she had then to Eva. Finally, Eva gave
14 of whatever she had to Zoe. As a result, they each had the same number of erasers. How many erasers did Zoe have at first?
|
Zoe |
Pamela |
Eva |
Total |
Before 1 |
? |
1 u |
|
900 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
3 p |
|
900 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
2 p |
|
|
Before 3 |
|
|
4 boxes |
900 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
3 boxes |
|
After 3 |
1 group |
1 group |
1 group |
900 |
3 groups = 900
1 group = 900 ÷ 3 = 300
1 group = 3 boxes 3 boxes = 300
1 box = 300 ÷ 3 = 100
2 p = 1 group
1 p = 300 ÷ 2 = 150
3 p = 3 x 150 = 450
3 p = 2 u
2 u = 450
1 u = 450 ÷ 2 = 225
Number of erasers that Zoe had at first
= 1 group - 1 box + 1 u
= 300 - 100 + 225
= 425
Answer(s): 425