#15
Double Down
| Difficulty: | Elementary |
| Topics: |
Write a function which doubles a number.
 | (= (__ 2) 4) |
| (= (__ 3) 6) |
| (= (__ 11) 22) |
| (= (__ 7) 14) |
| Difficulty: | Elementary |
| Topics: |
| (= (__ 2) 4) |
| (= (__ 3) 6) |
| (= (__ 11) 22) |
| (= (__ 7) 14) |