Perry and Lee had 81 notebooks. After Perry gave 25 notebooks to Lee. Lee, in return, gave half of his notebooks to Perry. In the end, Perry had twice as many notebooks as Lee. How many notebooks did Perry have at first?
| |
Perry |
Lee |
Total |
| Before |
1 u + 25 |
2 u - 25 |
81 |
| Change 1 |
- 25 |
+ 25 |
|
| After 1 |
1 u |
2 u |
|
| Change 2 |
+ 1 u |
- 1 u |
|
| After 2 |
2 u |
1 u |
81 |
Total number of notebooks that Perry and Lee had at first and in the end remains unchanged.
Total number of notebooks
= 2 u + 1 u
= 3 u
1 u = 81 ÷ 3 = 27
Number of notebooks that Perry had at first
= 1 u + 25
= 27 + 25
= 52
Answer(s): 52
