Charlie and David had 57 pencils. After Charlie gave 22 pencils to David. David, in return, gave half of his pencils to Charlie. In the end, Charlie had twice as many pencils as David. How many pencils did Charlie have at first?
| |
Charlie |
David |
Total |
| Before |
1 u + 22 |
2 u - 22 |
57 |
| Change 1 |
- 22 |
+ 22 |
|
| After 1 |
1 u |
2 u |
|
| Change 2 |
+ 1 u |
- 1 u |
|
| After 2 |
2 u |
1 u |
57 |
Total number of pencils that Charlie and David had at first and in the end remains unchanged.
Total number of pencils
= 2 u + 1 u
= 3 u
1 u = 57 ÷ 3 = 19
Number of pencils that Charlie had at first
= 1 u + 22
= 19 + 22
= 41
Answer(s): 41
