Question

How long would a boy takes to complete one round of circular park whose radius is 210m ,if his speed is 3km per hour.

Answer 1

I think 1.05mins must be required

Answer 2

Here is your answer.....

The radius of the circular park = 210m = 0.21 km

Circumference of circular park = 2πr
                                                     = 2×3.14×0.21 km
                                                     = 1.3188 km

Speed of boy = 3 km/hr

Time = 1.3188/3 hr
         = 0.4396 hr
         ≈ 26 minutes

The boy will take 26 minutes to complete one round of circular park.

I hope it helps you ^_^