Time and Distance Questions

Two cars travel from city A to city B at a speed of 36 and 54 km/hr respectively. If one car takes 3.5 hours lesser time than the other car for the journey, then the distance between City A and City B is

A racing car going at an average speed of 108 km/hr takes 15 minutes to complete a lap on a racing track. By how much should it increase its speed (inkm/hr) to complete the lap in 12 minutes?

What should be the average speed of a car to cover a distance of 189 km in 3.5 hours?

If a boat goes upstream at a speed of 21 km/h and comes back the same distance at 28 km/h. What is the average speed (in km/hr) for the total journey?

Ravindra walks at 6 km/hr and Riya cycles at 11 km/hr towards each other. What was the distance between them when they started if they meet after 42 minutes?

The ratio of speeds of X and Y is 5:7. Y covers a distance of 420 km in 3 hours. What is the speed of X?

A truck moves at the speed of 90 km/hr after repairing and moves at the speed of 80 km/hr before repairing. It covers x distance in 8 hours after repairing. How much time (in hours) will it take to cover 4x distance before repairing?

A train has to cover a distance of 900 km in 25 hours. What should be its average speed in meters/second?