The volumes of two cones are in the ratio 1 : 20 and the radii of the cones are in the ratio of 1 : 4. What is the length of the wire?  Choose the correct choice from the following choices:
A) A)2:5
B) B)2:7
C) C)2:2
D) D)4:5
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/(4)2h2   =&gt; h1/h2 = 4/5   i.e. h1 : h2 = 4 : 5   Answer: 4:5
<result>D</result>
The volumes of two cones are in the ratio 1 : 20 and the radii of the cones are in the ratio of 1 : 4. What is the length of the wire?