Little confused on this one

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Source: — Data Sufficiency |

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by Anurag@Gurome » Sun Jul 24, 2011 2:09 am
knight247 wrote:What is the value of m?
(1)8*m^2=8^2*m
(2)m is an integer
I assume 8^2*m in statement 2 means (8^2)*m not 8^(2m).

From statement 1, 8*(m^2) = (8^2)*m ----> 8m^2 - 64m = 0 ----> m(m - 8) = 0
Hence, value of m is either 0 or 8.

Now 0 and 8 are both integers. Hence statement 2 together with statement 1 doesn't add any new information. Hence, both statements together is not sufficient.

The correct answer is E.
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by knight247 » Sun Jul 24, 2011 2:30 am
Anurag,
You're right. Statement 1 says (8)(m^2)=(8^2)(m)
Ok, I have a bit of a silly question....Why can't I just cancel 8*m on either side and get m=8 ?

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by Anurag@Gurome » Sun Jul 24, 2011 3:00 am
knight247 wrote:Anurag,
You're right. Statement 1 says (8)(m^2)=(8^2)(m)
Ok, I have a bit of a silly question....Why can't I just cancel 8*m on either side and get m=8 ?
Because that will discard the possibility of m = 0.
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