A boat covers a distance of 80 km downstream in 8 hours, while it takes 10 hours to cover the same distance upstream. What is the speed (in km/h) of the boat in still water?

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.