Another problem giving me grief ...help!

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Another problem giving me grief ...help!

by elemat » Thu Oct 08, 2009 4:19 pm
Does anyone have any techniques, or "rules of thumb" to deal with number property questions / geometry problem like this. Also what's the quickets solution:

A cube has lenght x, a surface area y, and a volume z. Which of the following must be true?
a. (xy)/z - y/x = 0
b. ((x^2)y)/z - y/x = 0
c. xz/((x^2)y) - (x^2)/xy = 0
d. x(sqrt(y))/(sqrt(z)) - (x^2)/y = 0
e. sqrt(z)/xy - sqrt(y)/(x^2) = 0

Given the info provided i get this far:
y = 6x^2
z = x^3
Now what?

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elemat wrote:Does anyone have any techniques, or "rules of thumb" to deal with number property questions / geometry problem like this. Also what's the quickets solution:

A cube has lenght x, a surface area y, and a volume z. Which of the following must be true?
a. (xy)/z - y/x = 0
b. ((x^2)y)/z - y/x = 0
c. xz/((x^2)y) - (x^2)/xy = 0
d. x(sqrt(y))/(sqrt(z)) - (x^2)/y = 0
e. sqrt(z)/xy - sqrt(y)/(x^2) = 0

Given the info provided i get this far:
y = 6x^2
z = x^3
Now what?
now put the values in the option and check which is correct
B is the correct ans
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