Question

A cone is cut parallel to its base in 3 parts in such a way that the height of each part is same. Find the ratio of volume of these parts?

A 2:5:11 Correct Answer Incorrect Answer
B 1:7:19 Correct Answer Incorrect Answer
C 4:7:9 Correct Answer Incorrect Answer
D 1:3:7 Correct Answer Incorrect Answer

Solution

Volume of cone ABC = 1/3 π(r1)2 h ............(1) Volume of Frustrum BCED = 1/3 π(2r1)2 2h - 1/3 π(r1)2h = 7/3 π(r1)2 h ............(2) Volume of Frustrum DEGF = 1/3 π(3r1)2 3h - 1/3 π(2r1)2 2h = 19/3 π(r1)2 h ............(3)  Now, ratio = 1/3 π(r1)2 h: 7/3 π(r1)2 h: 19/3 π(r1)2 h = 1:7:19 

Practice Next
×
×