The curved surface area of a frustum cone is 25 𝝿mm2 . The larger circle area is12𝝿mm2.The total surface area is350𝝿mm2Find the smaller circle area of a cone

Sub Grade: 9

see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away

An Intiative by Sri Chaitanya

313mm2

323mm2

333𝝿mm2

313𝝿mm2

answer is D.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Area of bigger circle = 𝝿R2
12𝝿= 𝝿R2
R2= 12 (1)
CSA of frustum cone =𝝿(r+R)h
25 𝝿=(r+R)n
(r+R)h = 25 (2)
Given TSA = 350𝝿mm2
[(r+R)h+r2+R2]= 350𝝿
(R+r) h+r2+R2= 350 (3)
Put the value of equation (1) and (2)
In equation (3)
35+r2+12= 350
r2= 350-(35+12)
r2= 313
Area of smaller circle =𝝿r2
= 22/7*313
= 313 𝝿mm2

Watch 3-min video & get full concept clarity

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Online Course for IIT JEE

Best Online Course for NEET

Best Online Course for CBSE