A box contains 10 mangoes out of which 4 are rotten. Two mangoes are taken out together. If one of them is found to be good, then the probability that the other is also good, is

Let A be the event that the first mango is good. Then required probability is PBA=P(A∩B)P(A) Probability that both mangoes are good is p(A∩B)= 6C2 10C2 Probability that first mango is good is PA =C6,2C10,2+C6,1·C4,1C10,2PBA=PA∩BPA=C6,2C6,2+C(6,1)·C4,1=1539=513