The practice test shows Error even after giving the correct solution

Question

The practice test shows Error even after giving the correct solution, and I am not able to proceed further with the course. Pease suggest any solution for to resolve this and continue the reading.

Answer 1

First, understand the task. Then, understand the error you got, and the conditions for it to happen. Finally, find the cause and fix it.
If you want more specific hints, edit your question description and add:
1. An explanation of the task
2. A link to your code
3. A full description of the errors or wrong outputs you got
4. Example conditions which trigger the problem and which don't

Answer 2

1 Answer is right