Question

diameter of roller = 70 cm... length =100 cm ...in how many revolution it will cover 4400 m square playground

Answer 1

I have asked the same question just now,

I think the answer is 2000

Answer 2

We have to find curved surface area of cylinder

radius = diameter / 2 = 70/2=35cm
height = 100 cm
C.S.A. of cylinder = 2 π r h
                                 = 2 π x 35 x 100
                                 =7000π
                                 = 7000 x 22 / 7
                                 =22000 cm²
                                 =2.2 m²
 

area to be covered = 4400 m²  

No. of revolutions = total area t be covered / c.s.a. of cylinder roller
                               =4400 / 2.2 = 2000

2000 revolutions