Three girls, Eva, Abi and Wendy had a total of 4140 erasers. Some exchanges were made. First, Eva gave Abi as many erasers as Abi had. After that, Abi gave
14 of whatever she had then to Wendy. Finally, Wendy gave
14 of whatever she had to Eva. As a result, they each had the same number of erasers. How many erasers did Eva have at first?
|
Eva |
Abi |
Wendy |
Total |
Before 1 |
? |
1 u |
|
4140 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
4 p |
|
4140 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
3 p |
|
|
Before 3 |
|
|
4 boxes |
4140 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
3 boxes |
|
After 3 |
1 group |
1 group |
1 group |
4140 |
3 groups = 4140
1 group = 4140 ÷ 3 = 1380
1 group = 3 boxes 3 boxes = 1380
1 box = 1380 ÷ 3 = 460
3 p = 1 group
1 p = 1380 ÷ 3 = 460
4 p = 4 x 460 = 1840
4 p = 2 u
2 u = 1840
1 u = 1840 ÷ 2 = 920
Number of erasers that Eva had at first
= 1 group - 1 box + 1 u
= 1380 - 460 + 920
= 1840
Answer(s): 1840