$\"\"$

Radius of the spherical shell is $\"\"$ cm.

Thickness of the each shell is $\"\"$ cm.

Volume of the spherical shell is $\"\"$ .

Differentiate on each side with respect to $\"\"$ .

$\"\"$

Substitute corresponding values in the above expression.

$\"\"$

Volume is $\"\"$ .

$\"\"$

$\"\"$ .