Answer: 4/13
Step-by-step explanation:
There are 4 jacks (one of each suit) and 13 clubs. This gives 4+13 = 17 cards that are either jack or club. However, we double-counted the jack of clubs which means there are really 17-1 = 16 cards that are one or the other or both.
This is out of the 52 total mentioned. So we end up with the probability:
16/52 = (4*4)/(4*13) = 4/13