Question

The curved surface of a cylinder is 176cm² and its base area is 38.5cm². Find the volume of the cylinder. (π= 22/7)

Answer 1

We are Given CSA of cylinder= 176 cm²
   Area of base (Circle)= 38.5 cm²
  Let Radius = r

 then, Лr²=385/10
          22/7*r²=385/10
            so r²=385*7/10*22
                 r²= 49/4
             So, r, radius of cylinder = 7/2 cm ..................(1)

    We are also given CSA of cylinder= 176 cm² 
                                  2Лrh= 176 
                                  2*22/7*7/2*h= 176   [By Eqn (1) r=7/2] 
                             So, h= 8cm .......................................(2)

         Volume of Cylinder= πr²h
                                         = 22/7*(7/2)²*8
                                         =154*2
                                         =308 cm²

Answer 2

area of base=38.5cm²
∴πr²=38.5
22/7*r²=38.5
r²=38.5*7/22
r²=12.25
r=3.5
Curved surface area=176cm²
∴ 2πrh=176
2*22/7*3.5*h=176
h=8cm
∴ volume of cylinder=πr²*h
                                 =22/7*12.25*8
                                 =308cm³