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Unit digit of K

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by sunilrawat » Sat Jul 02, 2011 10:41 pm
K/60125= sq root 0.02681
(K^2)/60125^2 = 0.02681
K^2 = 60125^2 * 0.02681
unit digit of k^2 is 5.
unit digit of k is also 5.
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by silas » Sun Dec 18, 2011 6:05 pm
@MBA.Aspirant

You make a mistake by confusing 60125^2 * 0.02681 and 60125^2 * 1.
abcd.efgh written as a decimal will give d at the unit digit and not h, as you write.
Therefore, the unit digit of k cannot be 5.
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by pemdas » Sun Dec 18, 2011 11:59 pm
this is wrong.
sunilrawat wrote:K/60125= sq root 0.02681
(K^2)/60125^2 = 0.02681
K^2 = 60125^2 * 0.02681
unit digit of k^2 is 5.
unit digit of k is also 5.
please see the solution below
K/60125=sq root (0.02681)=sq root(2681/100000)

now imagine we have p=q*b+r, where r is remainder.
Here p=K, q=60125, b=0 and r=sq root(2681/100000)

Since our quotient, q> sq root (100000), we multiply sq root(2681) by 60125/sq root (100000) to obtain K

The only way to calculate this is to employ calculator which is supplied only for GRE exam not GMAT (!).

@MBA.Aspirant, are you posting GRE quant. question here?
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