Why lenght of k is 3 in the below code please explain

Question

https://code.sololearn.com/cozW655hSMC4/?ref=app

Answer 1

Please consult the Python lesson below:
https://www.sololearn.com/learn/Python/2484/

The asterisk allows you to pass an arbitrary number of values to a variable.

Answer 2

Teja Swaroop a is not a collection, it has no length

Answer 3

Why the output of k is[3,4,5]

Answer 4

Why it is showing error for lenght of a