Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:
The heights of two right circular cones are in the ratio 1 : 2 and the perimeters of their bases are in the ratio 3 : 4. Find the ratio of their volumes.
Answer
Answer (as printed):
Explanation
Let the radii of their bases be r and R and their heights be h and 2h respectively. 2 πr 3 r 3 4 Then, = ⇒ = ⇒ R = r. 2 πR 4 R 4 3 1 2 πr h 3 9 ∴ Ratio of volumes = 2 = = 9 : 32. 1 4 32 π r (2 h) 3 3 VOLUME AND SURFACE AREAS 771
Explanation as extracted from the printed page; notation may be imperfect.