Question

David's average driving speed for 5 hours journey was 55 km/h .During his first two hours of journey he drove at 60 km/h , and the last two hours he drove at 50 km/h . what was his speed for the fifth hour of the journey ?​

Answer 1

Answer:

55 km/hr

Step-by-step explanation:

Given that:

Average Speed = 55km/hr

Total Time taken = 5 hours

Speed for the first two hours = 60km/hr

Speed for the last two hours = 50km/hr

To find:

Speed during the third hour

We know that:

$Speed =\frac{Distance}{Time}\\\\Distance = Speed*Time\\Distance = 55*5 = 275 km$

Hence, Total Distance = 275 km

Distance covered in the first two hours = 60*2 = 120 km

Distance covered in the last two hours = 50*2 = 100 km

Distance left = 275-(120+100) = 275-220 = 55 km

Hence, Speed during the third hour = $\frac{55}{1} = 55 km/hr$