The volume of a solid right circular cone is 600π cm3, and the diameter of its base is 30 cm. The total surface area (in cm2) of the cone is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 480 π
|
Understanding |
Application |
|
Volume of the solid right circular cone is 600π cm3, And Diameter of base = 30 cm So, Radius = 30/2 = 15 cm |
So, 1/3(πr2h) = 600π (15 × 15) × h = 1800 h = 8 cm
|
|
h = 8 cm and r = 15 cm |
So, l = √(r2 + h2) l = √(225 + 64) = √289 l = 17 cm |
|
Total surface area of cone = πr2 + πrl |
So, Total surface area = π(152 + 15 × 17) = 480 π |
Short Trick:
In this question answer will be multiple of 3. So check the option which will be divisible by 3.
Only option 2 is divisible by 3.