Agreed. It was difficult determining for certain what was being asked for. I suggest something like the below wording at the end of the Task section:

The function should return the minimum number of socks that must be pulled out such that you are guaranteed at least num_of_pa_want pairs (of size num_of_soc_in_pair) of matching socks.

You didn't even mention anywhere in this kata what should the function return, only what it recieves.