Tanks A and B are identical inverted conical tanks. A is completely filled with water. B is filled with water to half its depth. The ratio of the areas of the top free water surfaces in the two tanks is
a) 2 : 1 b) 4 : 1 c) 6 : 1 d) 8 : 1 e) 10 : 1
Answer b
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s91arvindh
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Hi s91arvindh,
Cones are exceptionally rare on the GMAT. While you'll likely see 1 "solid" question on the GMAT, it will likely be a rectangular solid, cube or cylinder.
That having been said, the question appears to be asking for the 'areas' of the surface water at the "top." Since the "top" would be a circle, you can TEST VALUES by plugging in a number for the radius.
If the full cone has R = 2...
then the "full" cone has a "top" surface area of pi(R^2) = pi(2^2) = 4pi
then the half-cone has R = 1....
and the "half-full" cone has a "top" surface area of pi(R^2) = pi(1^2) = 1pi
The ratio of the two areas is 4:1
Final Answer: B
GMAT assassins aren't born, they're made,
Rich
Cones are exceptionally rare on the GMAT. While you'll likely see 1 "solid" question on the GMAT, it will likely be a rectangular solid, cube or cylinder.
That having been said, the question appears to be asking for the 'areas' of the surface water at the "top." Since the "top" would be a circle, you can TEST VALUES by plugging in a number for the radius.
If the full cone has R = 2...
then the "full" cone has a "top" surface area of pi(R^2) = pi(2^2) = 4pi
then the half-cone has R = 1....
and the "half-full" cone has a "top" surface area of pi(R^2) = pi(1^2) = 1pi
The ratio of the two areas is 4:1
Final Answer: B
GMAT assassins aren't born, they're made,
Rich
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s91arvindh
- Junior | Next Rank: 30 Posts
- Posts: 22
- Joined: Sat Apr 19, 2014 5:24 am
Hi Rich,
Thanks a lot for the calcification .
These questions are given for practice.
Thanks
s91arvindh
Thanks a lot for the calcification .
These questions are given for practice.
Thanks
s91arvindh
