The difference between inside and outside surfaces of a cylindrical tube 14cm long is 88sq. cm. If the volume of the tube is 176 cubic cm, find the inner and outer radii of the tube.

Explanation

Outside surface area-inside surface area=`88`
`2piRh-2pirh`=`88`
`2xx22//7xx(R-r)xx14`=`88`
`2xx22xx(R-r)xx2`=`88`
`R-r`=`88//2xx22xx2=1......(a)`
External volume-internal volume=`176 cm^3`
`piR^2h-pir^2h`=`176`
`pi(R^2-r^2)h`=`176`
`22//7xx(R-r)(R+r)xx14`=`176`
`R+r`=`176//22xx2=4........(b)`
By adding both the equations
`2R=5`
`R`=`2.5 cm`
Therefore,`r=R-1`=`1.5 cm`.
Inner radii=`1.5`