Question

Thee inner circumference of circultra track is 220 m .the track is 7m wide calcalculate the cost of putting up fence along the outer circle at rate of rs:21p/m

Answer 1

First we will find the inner radius by using the circumference and by formula of
$2\pi r$
The answer must come as 35m(radius)
we know the width between inner and outer track which is 7 m, So the total radius will be 35+7=42, and circumference will come out to be 264m..which is the length of fence and total cost = 21rs×264=5544rs.