What is the average speed of the car if it covers 200 km in 5 h?

A man walks on a straight road from his home to a market 2.5 km away with a speed of 5 km. h^(-1) . Finding the market closed he instantly turns and walks back home with a speed of 7.5 km. h^(-1) . What is the average speed of the man over the interval of time (i) 0 to 30 min (ii) 0 to 50 min (iii) 0 to 40 min? [Note: you will appreciate speed as total path length divided by time and not as magnitude of average velocity. You would not like to tell the tired man on his return home that his average speed was zero! ]

A person travels half of a distance at an average velocity of 24 km. h^(-1) . At what average velocity should he move to cover the second half of the path so that his average velocity for the total path becomes 32 km . h^(-1) ?

An express train takes 1 hour less than a passenger train to travel 132 km between Mysore and Bangaluru (without taking into consideration the time they stop at intermediate stations). If the average speed of the express train is 11km/h more than that of the passenger train, find the average speed of the two trains.

An automobile driver travels from plain to a hill station 120 km distant at an average speed of 30 km per hour. He then makes the return trip at an average speed of 25 km per hour. He covers another 120 km distance on plain at average speed of 50 km. per hour . His average speed over the entire distance of 360 km will be

A motor car covers (1)/(3) part of total distance with velocity v_(1) = 10 "km.h"^(-1) , the second (1)/(3) part with velocity v_(2) = 20 "km.h"^(-1) and the rest with velocity v_(3) = 60"km.h"^(-1) . What is the average speed of the car?