The base diameter of a cone is 14cm, and its volume is 462 cm3. Find its height. [Taken (pi = frac{22}{7})]
-
A.
3.5cm -
B.
5cm -
C.
7cm -
D.
9cm
Correct Answer: Option D
Explanation
From (V = frac{1}{3}pi r^2 h. hspace{1mm} r =frac{14}{2}\
462 = frac{1}{3} times frac{22}{7} times 7^2 times h \
h = frac{3 times 462}{22 times 7}\ h = 9)