Question

A car moves from A to B with a speed of 30 km/h and from B to A with a speed of 20 km/h. What is the average speed of the car?​

Answer 1

Explanation:

1. A to B ,time = distance / speed = s /30

2. B to A , time = distance/ speed = s /20

average speed = total distance/ total time

= 2s / ( s/30 + s/20)

= ( 2 x 30 x20 )/ 50 = 120/5 = 24Km,/ h

Answer 2

Answer:

Average speed is 24 Km/h.

Explanation:

Given :-

A to B (Speed) = 30 Km/h

B to A (Speed) = 20 Km/h

To find :-

Average speed of the car.

Solution :-

Let the distance (A to B) be x km

Let the distance (B to A ) be x km

Then, we know :

• Speed = Distance/Time

So, Time taken (A to B) = x/30 h

And, Time taken (B to A ) = x/20 h

We know,

• Average speed = Total distance/Total time

So, (x + x)/(x/30 + x/20)

• (2x)/(2x + 3x)/60
• (2x)/(6x/60)
• 2x × 12x
• 2 × 12
• 24

∴ Average speed is 24 Km/h.