SSC CPO 2022 PYQ — Question 102

The correct answer is Option 1 i.e. 2772 cm², 4158 cm².

We know that, 

Curved surface area = 2πr²

The total surface area = 3πr²

Now, 

According to the question,

Radius of hemisphere = 42/2 = 21 cm

Now,

CSA of the hemisphere = 2π(21)²

⇒ 2(22/7)(441) = 19404/7 = 2772 cm²

Now, TSA of the hemisphere

TSA = 3π(21)²

⇒ 3(22/7)(441) = 29106/7 = 4158 cm²

Thus

The curved surface area and the total surface area of the hemisphere are 2772 cm² and 4158 cm².