If the outer diameter of a spherical shell is 18 cm and inner diameter is 12 cm, then find the volume of metal contained in the shell (take π = 3.14) correct to two places of decimal.

Correct option is B

Given:

External diameter of sphere =18cm

Internal diameter of sphere =12cm

Formula Used:

​$$Volume \ of \ hollow \ sphere =\frac{4}{3}\times\pi \times (r_1^3 - r_2^3)$$​​

Solution:

External radius of sphere = $$r_{1} = \frac{18}{2} = 9cm$$​​

Internal radius of sphere = $$r_{2} = \frac{12}{2} = 6cm$$

Volume of sphere = $$\frac{4}{3}\times\pi \times ((9)^{3} - (6)^{3})$$​​

​$$= \frac{4}{3}\times 3.14 \times ((729 -216)$$​​

​$$= \bf 2147.76 cm^{3}$$​​