Question

the difference between the inner and outer surface of a cylendrical pipe is 88sq cm.if the height of the cylendrical pipe is 14cm and volume is 176 cube cm,find the inner and the outer radii

Answer 1

H = 14 cm

2 π R H - 2 π r H = 88 cm²
  2 π H (R - r) = 88

 R - r = 88 / (2 π * 14) =  1 cm

It is not clear if the volume of the material is given OR, the external volume of the pipe is given.

case 1)
        Volume of the material in the pipe is = 176 cm³
               π R² H - π r² H = 176
                 R² - r² = 176 /(π * 14) =  4
                 (R+r)(R-r) = 4
                   R+r = 4 cm  as  R-r = 1 cm
         solving these two equations,  we get  R = 2.5 cm and r = 1.5 cm
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case 2)
       external volume of the pipe = 176 cm³
           π R² H = 176 cm³
               R² = 176 / (π*14) = 4
             R = 2 cm
         r = 1 cm