Ryan and Ethan had 51 pens. After Ryan gave 17 pens to Ethan. Ethan, in return, gave half of his pens to Ryan. In the end, Ryan had twice as many pens as Ethan. How many pens did Ryan have at first?
| |
Ryan |
Ethan |
Total |
| Before |
1 u + 17 |
2 u - 17 |
51 |
| Change 1 |
- 17 |
+ 17 |
|
| After 1 |
1 u |
2 u |
|
| Change 2 |
+ 1 u |
- 1 u |
|
| After 2 |
2 u |
1 u |
51 |
Total number of pens that Ryan and Ethan had at first and in the end remains unchanged.
Total number of pens
= 2 u + 1 u
= 3 u
1 u = 51 ÷ 3 = 17
Number of pens that Ryan had at first
= 1 u + 17
= 17 + 17
= 34
Answer(s): 34
