The volume of a cone of height 3cm is 38(frac{1}{2})cm3. Find the radius of its…

The volume of a cone of height 3cm is 38(frac{1}{2})cm³. Find the radius of its base. [Take (pi = frac{22}{7})]

Correct Answer: Option B

Explanation

Using V = (frac{3}{1} pi r^2h),
so, 38(frac{1}{2} = frac{1}{3} times frac{22}{7} times r^2 times 3)
(frac{77}{2} = frac{22}{7} times r^2)
r² = (frac{77 times 7}{2 times 22})
r² = (frac{49}{4})
Hence, r = (sqrt{frac{49}{4}})
= 3(frac{1}{2})