Time and Distance - General Questions

A car covers 600 km in 5 hours. At what speed must it travel to cover the same distance in 3 hours?

Express a speed of 70 m/s in km/hr.

If a boy walks from his house to school at 3 km/hr, he is 23 minutes late. If he walks at 4 km/hr, he is 22 minutes early. What is the distance from his house to school?

A car travels from A to B at 45 km/hr and returns from B to A at 90 km/hr. What is the average speed for the whole journey?

How far does a cyclist travel in 40 minutes at a speed of 45 km/hr?