Time and Distance - General Questions

A car travels from A to B at 36 km/hr and returns from B to A at 45 km/hr. What is the average speed for the whole journey?

Express a speed of 54 km/hr in metres per second.

If a boy walks from his house to school at 4 km/hr, he is 23 minutes late. If he walks at 5 km/hr, he is 34 minutes early. What is the distance from his house to school?

How far does a cyclist travel in 30 minutes at a speed of 40 km/hr?

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