Question

The total surface area of a solid sphere is 80 cm. It is split into two hemispheres. What is the surface area of the resulting hemisphere?

• A. 20
• B. 40
• C. 80
• D. 60

Answer 1

The correct option is D

60

We know that the Total Surface Area of a sphere of radius $r$ = $4\pi r^2$
Given that $4\pi r^2$ = 80
$⟹\pi r^2=20$
Now, the total surface area of a hemisphere of radius $r$ = $3\pi r^2$
Thus, the total surface area of the resulting hemisphere = $3\pi r^2$ = $3\times 20=60$