Question

A man runs around a circular field of radius 50 cm at an speed of 12 km/hr. What time is taken by the man to make twenty rounds of the field ?

Answer 1

Circumference=2*π*50

= 100*π

=314m=0.314km

Time taken=dist./speed

314/1000 * 12 = 0.26hr= 15.6mins

Answer 2

Answer:

Step-by-step explanation:

Circumference of circle=2πr

=2×22/7×1/2

=22/7m

Distance covered in 20 rounds=20×22/7

=440/7m

Speed=12km/hr

=12×5/18

10/3 m/sec

TIME=DISTANCE/SPEED

=440/7×3/10

132/7 SEC