The curved surface area of a cylindrical pillar is 264 sq.m and its volume is 924 cub.m. Find the ratio of its diameter to its height
Answers:
A) 7 : 9  B) 7 : 3  C) 7 : 7  D) 7 : 6  E) 7 : 1

Rationale: explanation : { \ color { black } \ frac { \ prod r ^ { 2 } h } { 2 \ prod rh } = \ frac { 924 } { 264 } } { \ color { black } \ rightarrow r = \ frac { 924 } { 264 } \ times 2 = 7 m } { \ color { black } and \ ; \ ; 2 \ prod rh = 264 \ rightarrow h = ( 264 \ times \ frac { 7 } { 22 } \ times \ frac { 1 } { 2 } \ times \ frac { 1 } { 7 } ) = 6 m } { \ color { black } \ therefore } required rato = { \ color { black } \ frac { 2 r } { h } } = { \ color { black } \ frac { 14 } { 6 } = 7 : 3 } answer : b ) 7 : 3
Answer: B