The volumes of two cones are in the ratio 1 : 20 and the radii of the cones are in the ratio of 1 : 2. What is the ratio of their heights?	Choose the correct choice from the following answers
A) A)2:5  B) B)2:7  C) C)1:5  D) D)2:1  E) E)2:9
The volume of the cone = (1/3)πr2h   Only radius (r) and height (h) are varying.   Hence, (1/3)π may be ignored.   V1/V2 = r12h1/r22h2 =&gt; 1/20 = (1)2h1/(2)2h2   =&gt; h1/h2 = 1/5   i.e. h1 : h2 = 1 : 5   Answer: 1:5
<result>C</result>
The volumes of two cones are in the ratio 1 : 20 and the radii of the cones are in the ratio of 1 : 2. What is the ratio of their heights?