Means of transport

A doctor is to visit a patient. From the past experience, it is known that the probabilities that he will come by train, bus , scooter or by other means of transportation are respectiely 3/10,1/5,1/10 or 2/5 . The probabilities that he will be late are 1/4,1/3 and 1/12 if he comes by train, bus and scooter respectively but if he comes by other means of transport, then he will not be late. If the arrives late, find the probability that he comes by train.

The distance betweenn two place A and B is 180 km by road adn 120 km by air. An aeroplane takes 20 min to go from A to B whereas a deluxe bus strarting at A takes 5h to reach B. Find the average speed and average velocity by both means of transport) (Ignore the vertical ascent of aeroplane)

The probabilities that a Man Makes a journey by car, Motor cycle or on foot are (1)/(2),(1)/(6),(1)/(3) respectively. The probabilities of an accident when he uses these means of transport are (1)/(5),(2)/(5) and (1)/(10) respectively. If he met an accident then the probability that he is travelling on foot is

A cadiadate has to reach the examination centre in time, Probality of him going by bus or scooter or by other means of transport are (3)/(10),(1)/(10) ,(3)/(5) respectively. The probability of getting late , if the travels by bus is 1/4 ,1/3 if he travells by scooter and 0 for any other medium. But he reaches in time if the uses any mode of transport . He reached late at the centre. The probability that he travelled by bus is -