Question

Hello! Girls and boys please help me with this question... solve this last question please....

Answer 1

the volume of metal used =
$\frac{22}{7} \times 14 \times ( {9}^{2} - {8}^{2} ) =$
$= 44 \times 17 \\ = 748 \: {cm}^{3}$
and the mass of pipe is =748×8.5= 6358 gram or 6.358kg