A person crosses 4200 m long bridge in 25 minutes. Find his speed in kmph:

Correct option is B

Given:
Distance = 4200 m
Time = 25 minutes
Formula Used:
Speed = $$\frac{Distance}{Time}$$​​
To convert m/min to km/h, multiply by 60/1000.
Solution:
Calculate the speed in meters per minute:
Speed = $$\frac{4200}{25}$$​ = 168 m/min
Convert the speed into km/h:
Speed = 168 × $$\frac{60}{1000}$$​ = 168 × 0.06
Speed = 10.08 km/h
Final Answer
So the correct answer is (b)