A bus maintains an average speed of 60 km/h while going from station P to Q and maintains an average speed of 90 km/h while returning along the same route. What is the average speed of the bus for the entire journey?

Ramesh covers 56 part of the total distance by bus and the remaining 36 km by car. What is the total distance of his journey?

A person covers a distance of L km in 12 hours. If he increases his speed by 10 m/s, he covers the same distance in 8 hours. Which of the following statements is/are correct? I. The value of L is 760 km. II. The original speed of the person is 72 km/h.