Quantitative Aptitude Ques 1962

Question: What is the appropriate total surface area of a right circular cone of height 14 cm and base radius 7 cm? [IBPS (PO/MT) 2015]

Options:

A) 510

B) 511

C) 490

D) 505

E) 499

Show Answer

Answer:

Correct Answer: E

Solution:

  • Height of cone, $ h=14cm, $ Radius of cone, $ r=7cm $

$ \therefore $ Slant height, $ l=\sqrt{h^{2}+r^{2}}=\sqrt{14^{2}+7^{2}} $ $ =\sqrt{196+49}=\sqrt{245}=15.65 $ So, total surface area of cone $ =\pi r(l+r) $ $ =\frac{22}{7}\times 7(15.65+7)\approx 499 $