If the curved surface area of a solid cylinder is one-third of its total surface area, then what is the ratio of its diameter to its height?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 4 : 1.
Given,
2πrh : 2πr(r + h) = 1 : 3
where, r = radius and h = height (of cylinder)
h : (r + h) = 1 : 3
So,
h = x, r = 2x
d = 2r = 2(2x) = 4x
Hence,
d : h = 4x : x = 4 : 1