Question

how long will a man take to make a round of a circular field of a radius 21 m cycling at the speed of 8 kilometre per hour​

Answer 1

Answer:

circumference of the field= 2× 22/7×21

circumference =132 m

TIME=DISTANCE/SPEED

$time = \frac{132}{8 \times 1000} (in \: hours) \\ time = \frac{132 \times 3600}{8000}(in \: seconds) = 594 \: seconds$

Time =594/60=9.9 minutes

So time taken is 594 seconds or 9.9 minutes

Answer 2

mAccording to question:

Radius of circle=21m

Speed of cycle=8km/hr.

So the required time will be:

2*22/7*21=132m

now, time=distance\time

132/2.22= 59 second.