2023 · Q23
solid circular metallic disc of radius 12 inches and thickness 4 inches is melted and shaped into a solid disc of radius 16 inches. What is the thickness of the new disc in inches?
General Mental Ability, Quantitative Aptitude and StatisticsNumber system and arithmetic
- A2
- B2.25
- C2.50
- D2.75
Explanation
Volume is conserved on melting: pi x 12^2 x 4 = pi x 16^2 x h, so h = (144 x 4)/256 = 2.25 inches. Option A (2) is an eyeball error. Hence B.