Question

A cylindrical powder tin of 15 cm of height and 14 cm of radius is filled with water. The powder tin is emptied to make a conical heap of water on the ground. If the height of the conical heap is 42 cm, what is approximate value of the radius? (Use $\pi$ = 3).

• A. 14 cm
• B. 16 cm
• C. 18 cm
• D. 20 cm

Answer 1

The correct option is A 14 cm

Volume of powered tin = Volume of the cone = $\pi r^{2}h\Rightarrow 3\times 14\times 14\times 15$

Volume of conical heap = Volume of the cone = $\frac{1}{3}\pi r^{2}h=\frac{1}{3}\times 3\times r^2\times 42$

On equating, we get

$3\times 14\times 14\times 15=\frac{1}{3}\times 3\times r^2\times 42$

$26,460/126=r^2$

$210=r^2$

$r=14cm$