Question

1)The volume of a right circular cone is $110m^3$ and diameter is $2\sqrt{15}$.calculate A)slate height
B)CSA
C)Height of cone
2)The ratio of base radius to slant height of a right circular cone is 3:2.Calculate the ratio of total surface of cylinder to curved surface of the cone .
3)A metal cylinder has height 7m.The inner radius of cylinder is 1m and outer radius is 1.5cm .calculate total surface area.

Answer 1

Volume =$11m^3$
$d=2\sqrt{15}mr=\frac{2\sqrt{15}}{2}=\sqrt{15}m$
$\pi r^{2}h=110h=\frac{110}{\pi r^2}=\frac{110\times 7}{22\times 15}=\frac{10\times 7}{2\times 15}=\frac{7}{3}m$
$CSA=2\pi rh=2\times \frac{22}{7}\times \sqrt{15}\times \frac{7}{3}=2\times 22\times \sqrt{15}\times \frac{1}{3}=44\sqrt{\frac{5}{3}}{m}^2$