cube problem!!!

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cube problem!!!

by yasem77 » Thu May 21, 2009 4:25 am
Approximately 90 percent of the volume of a certain cube that is floating in a tank of water is beneath the surface. If 6.4 cubic centimeters of the cube is above the surface of the water, what is the approximate length, in centimeters, of an edge of the cube?
(A) 10
(B) 8
(C) 6
(D) 4
(E) 2

Thanks for any help!

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by Svedankae » Thu May 21, 2009 4:44 am
Id go with (D) since 4*4*4 = 64 which is the volume of the whole cube since 6.4 cubic centimeters resemble 10% of it.

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by Davincii » Thu May 21, 2009 5:39 pm
I go with D

10% = 6.4
100% = 64

x^3 = 64
x = 4

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by yasem77 » Sun May 24, 2009 11:19 am
thanks a lot!

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Re: cube problem!!!

by Scott@TargetTestPrep » Mon May 25, 2020 11:03 am
yasem77 wrote:
Thu May 21, 2009 4:25 am
Approximately 90 percent of the volume of a certain cube that is floating in a tank of water is beneath the surface. If 6.4 cubic centimeters of the cube is above the surface of the water, what is the approximate length, in centimeters, of an edge of the cube?
(A) 10
(B) 8
(C) 6
(D) 4
(E) 2

Solution:

We see that 6.4 cubic cm of the cube is 10% of the volume of the cube. Therefore, the volume of the entire cube is 64 cubic cm, and hence its edge is 3^√64 = 4.

Answer: D

Scott Woodbury-Stewart
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