Radius of hemisphere is thrice than that of a sphere. What is the ratio of total surface area of hemisphere to that of sphere?
Let radius of sphere = $$r$$ cm and radius of hemisphere = $$3r$$ cm
Ratio of surface area = $$\frac{3\pi (3r)^2}{4\pi r^2}$$
= $$\frac{27}{4}$$
=> Ans - (C)
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