Question

19.
A car moves from A to B with a speed of
30 kmph and from B to A with a speed of
20 kmph. What is the average speed of the
car?
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Answer 1

Answer:

hey mate

Explanation:

The answer is 24km/h.

Answer 2

Let the distance from A to B (and B to A) be x

From A to B :-

Distance covered = x km

Speed = 30 km/h

Time taken = Distance / Speed

= x/30 h

From B to A :-

Distance covered = x km

Speed = 20 km/h

Time taken = Distance / Speed

= x/20 h

Total journey :-

Total Distance covered = (x + x) km = 2x km

Total Time taken = (x/30 + x/20) h = (5x/60) h = x/12 h

Average speed = Total Distance / Total time

= 2x / (x/12)

= 2x × (12/x)

= 2 × 12

= 24 km/h

Hope it Helps!!