The volumes of two cones are in the ratio of 3 : 2 and their radii are in the ratio 3 : 4. The ratio of their heights is:
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Correct answer: A
Explanation
The correct answer is option 1 i.e. 8:3
Ratio of volumes of two cones = 3 : 2
Ratio of radii of the two cones = 3 : 4
The volume of cone = (1/3)πr2h
Let x be a common factor. So, the ratio of their radii is 3x : 4x.
The volume of the first cone, V1 = (1/3)π(3x)2h1 = (1/3)π9x2h1
The volume of the second cone, V2 = (1/3)π(4x)2h2 = (1/3)π16x2h2
The ratio of volumes of the two cones = 3 : 2
V1/V2 = 3/2
9x2h1/16x2h2 = 3/2
h1/h2 = 48/18
h1/h2 = 8/3