Sam and Ethan had 87 pens. After Sam gave 22 pens to Ethan. Ethan, in return, gave half of his pens to Sam. In the end, Sam had twice as many pens as Ethan. How many pens did Sam have at first?
| |
Sam |
Ethan |
Total |
| Before |
1 u + 22 |
2 u - 22 |
87 |
| Change 1 |
- 22 |
+ 22 |
|
| After 1 |
1 u |
2 u |
|
| Change 2 |
+ 1 u |
- 1 u |
|
| After 2 |
2 u |
1 u |
87 |
Total number of pens that Sam and Ethan had at first and in the end remains unchanged.
Total number of pens
= 2 u + 1 u
= 3 u
1 u = 87 ÷ 3 = 29
Number of pens that Sam had at first
= 1 u + 22
= 29 + 22
= 51
Answer(s): 51
