Question

Pratik walks from Andheri to Bandra at 8 km/h and comes back from
Bandra to Andheri at 12 km/h. What is his average speed for the entire
journey?
8.8
9.6
10.2.
11.4​

Answer 1

Answer:

• Average speed for the entire journey is 9.6 km/h.

Explanation:

Let, distance between Andheri and Bandra be x km

then, while going from Andheri to Bandra

• Distance covered = x  km
• speed = 8 km/h
• Let, time taken = t₁  hrs

so,

→ speed = distance / time

→ 8 = x / t₁

→ t₁ = (x / 8)   hrs

Now, While going from Bandra to Andheri

• Distance covered = x  km
• speed = 12 km/h  
• let, time taken = t₂  hrs

so,

→ speed = distance / time

→ 12 = x / t₂

→ t₂ = (x / 12)  hrs

Therefore,

Calculating total time taken for the journey

→ Total time taken, t = t₁ + t₂

→ t = ( x / 8 ) + ( x / 12 )

→ t = ( 3 x + 2 x ) / 24

→ t = (5 x / 24)   hrs

and, total distance covered during the journey will be = (2 x)   km

So, Using formula

→ Average speed = total distance covered / total time taken

→ Average speed = ( 2 x ) / ( 5 x / 24 )

→ Average speed = ( 2 x ) · ( 24 ) / ( 5 x )

→ Average speed = 48 / 5

→ Average speed = 9.6  km/h

Hence,

• Average speed for the entire journey is 9.6 km/h.

Answer 2

Step-by-step explanation:

Given : -

• Pratik walks from Andheri to Bandra at 8 km/h

• comes back from Bandra to Andheri at 12 km/h.

To Find : -

• What is his average speed for the entire journey?

Solution : -

Average speed = First distance × return distance × 1/10

Average speed = 8 × 12 × 1/ 10

Average speed = 96 × 1 / 10

Average speed = 96/10

Average speed = 9. 6

Hence the b option is correct

More information : -

• The average speed of an object is the total distance traveled by the object divided by the elapsed time to cover that distance. It's a scalar quantity which means it is defined only by magnitude.

• the rate at which someone or something moves or operates or is able to move or operate.