Question

Find the volume of the frustum cone whose base and top radius is $5$ mm and $2$ mm respectively. The height of the cone is $15$mm. (Use $\pi$ = 3.14).

• A. $612.3$ mm${}^3$
• B. $602.3$ mm${}^3$
• C. $622.3$ mm${}^3$
• D. $632.3$ mm${}^3$

Answer 1

Answer: (A)

$612.3$ mm${}^3$

Volume of frustum $=\frac{1}{3}\times \pi (R^2+r^2+Rr)\times h$

$=\frac{1}{3}\times 3.14(5^2+2^2+5\times 2)\times 15$

$=15.70(25+4+10)=15.70\times 39$

$=612.3$ ${mm}^3$