Two trains P and Q of lengths 320 m and 540 m, respectively, are running in the same direction on parallel tracks at 108 km/h and 144 km/h, respectively. How much time will the trains take to cross each other completely?

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.