From a solid cylinder whose height is 8 cm and of base radius 6 cm a conical cavity of height 8 cm a...........

Quantitative Aptitude (CDS) Mensuration 3D

From a solid cylinder whose height is 8 cm and of base radius 6 cm, a conical cavity of height 8 cm and of base radius 6 cm is formed by hollowing out. What is the inner surface area of the cavity?

6?? square cm

8?? square cm

10?? square cm

60?? square cm

छोटे Courses बड़े Results

Master Mensuration 3D

Prepare through Micro-courses

Try Now

Explanation:

As, the conical cavity in the cylinder is hollowed out.
Therefore, inner surface area of the cavity is curved surface area of the cone.
Thus, curved surface area of cone = $\pi$ rl= $\pi$ ×6×√82+62
= $\pi$ ×6×√100 = $\pi$ ×6×10=60 $\pi$
Hence inner surface area of cavity = 60 $\pi$ sq. cm