A hemispherical dome of a tomb having a diameter of 3.5 m is to be painted. If the cost of painting is 20 paise per cm2, then what is the cost (in ₹) of painting the dome from inside? Take =
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. ₹38,500
Given that
The diameter of a hemispherical dome is 3.5 m
then the radius of dome is 3.5/2 = 1.75 m = 175 cm
The cost of painting is 20 paise per cm2
Formula used
The curved surface area of a hemisphere = 2πr2
Calculation
The curved surface area = 2 × (22/7) × 1752 = 192500 cm2
The cost of painting the dome from inside = 192500 × 0.2 = Rs. 38500