In speed problems, what should be noted if a question indicates a distance of 400 km covered in 5 hours?

In speed problems involving distance and time, noting that a distance of 400 km is covered in 5 hours typically implies a constant speed unless otherwise specified. This means that the average speed for the entire distance can be calculated by dividing the total distance by the total time.

For the given scenario, when you calculate the speed using the formula:

Speed = Distance / Time

you find:

Speed = 400 km / 5 hours = 80 km/hr.

This calculation shows that while the average speed for the journey is 80 km/hr, the question does not provide any details suggesting that the speed varies at different times. Thus, the statement that speeds vary at different times does not align with the information provided.

The aspect that needs to be emphasized is that as long as no variable speeds are mentioned in the question, it is generally assumed that either the speed is constant throughout the journey or that any variations average out to give the calculated speed. Therefore, the correct understanding for this scenario is that the average speed can be determined to be 80 km/hr, and it's most appropriately understood as implying a constant speed for the journey unless stated otherwise.