P(J/K) = 0.1 means that the probability of event J happening with respect to K is 0.1.However, since J and K are independent events, they are not related to each other. Thus, what ever the probability of event K is, it would not affect the probability of event J happening. So, P(J) would still be equal to 1.
Based on the given statements above, it is mentioned that both J and K are independent events. Therefore, in order to know what is the probability if J, we can still say that it is still 0.1 knowing that again, each of them is independent. I hope that answers your question.