Question 1 involves conditional probability, as it asks for the expected number of visits given that a patient has had at least one visit.
So P(X=x given X>0)= P(X=x and X>1)/P(X>0)
eg. P(X=1 given X>0)=P(X=1)/P(X>0)=0.2/0.5=2/5
Do the same for 2,3,4,5 and then find the expected value.