The probability that a regularly scheduled flight departs on time is P(A)=0.83; The probability that it arrives on time is P(B)=0.82; and the probability that it departs and arrives on time is P(AB)=0.78. Find the probability that a plane : 1) The probability of a plane arrives on time, given that it departed on time. 2) The probability of a plane departed on time, given that it arrived on time.