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If m and n are negative integers, what is the value of mn? [#permalink]
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29 Dec 2011, 08:45
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If m and n are negative integers, what is the value of mn? (1) m^n = 1/81 (2) n^m =  1/64 OPEN DISCUSSION OF THIS QUESTION IS HERE: ifmandnarenegativeintegerswhatisthevalueofmn108394.html
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Last edited by Bunuel on 23 Feb 2016, 02:06, edited 1 time in total.
Renamed the topic and edited the question.



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Re: If m and n are negative integers, what is the value of mn? [#permalink]
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29 Dec 2011, 10:18
C What's your doubt? 1. m=3,n=4; m=9, n=2 mn=12; mn=18 2. n=64,m=1; n=4, m=3 [m will always be odd] nm=64; mn=12 1+2 nm=12
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Re: If m and n are negative integers, what is the value of mn? [#permalink]
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29 Dec 2011, 19:49
no doubt. just double checking as the OA was B.



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Re: If m and n are negative integers, what is the value of mn? [#permalink]
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30 Dec 2011, 00:48
the answer is B
consider the first statement
u have m^n=1/81 cz both m and n are negative i.e. it should be (ve)^(ve) or in this case (9)^(2) or (3) ^(4) both of which satisfy the statement thus Insufficient
consider the 2nd statement
we have n^m= (1/64)
so the options can be (8)^(2) or (4)^(3)
cz minus sign is already there that means the exponent has to be odd (that is the only way we would get a negative sign out of the base. thus we have only one solution (4)^(3) which give n=4 and m=3 or mn=12 hence Sufficient



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Re: If m and n are negative integers, what is the value of mn? [#permalink]
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30 Dec 2011, 01:34
puneetkr wrote: the answer is B consider the 2nd statement
we have n^m= (1/64)
so the options can be (8)^(2) or (4)^(3)
there can one more solution: (64)^(1) it should be C) imo



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Re: If m and n are negative integers, what is the value of mn? [#permalink]
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30 Dec 2011, 07:09
d3thknell wrote: puneetkr wrote: the answer is B consider the 2nd statement
we have n^m= (1/64)
so the options can be (8)^(2) or (4)^(3)
there can one more solution: (64)^(1) it should be C) imo Yes It should be C...
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Re: If m and n are negative integers, what is the value of mn? [#permalink]
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23 Feb 2016, 02:07
dreambeliever wrote: If m and n are negative integers, what is the value of mn?
(1) m^n = 1/81 (2) n^m =  1/64 If m and n are negative inegers what is the value of m*n?(1) m^n=1/81 > as both m and n are negative integers then \(m^n=\frac{1}{81}=(9)^{2}=(3)^{4}\) > \(mn=18\) or \(mn=12\) (note that as negative integer in negative integer power gives positive number then the power must be negative even number). Not sufficient. (2) n^m=(1/64) > as the result is negative then \(m\) must be negative odd number > \(n^m=\frac{1}{64}=(4)^{3}=(64)^{1}\) > \(mn=12\) or \(mn=64\). Not sufficient. (1)+(2) Only one pair of negative integers \(m\) and \(n\) satisfies both statements \(m=3\) and \(n=4\) > \(mn=12\). Sufficient. Answer: C. OPEN DISCUSSION OF THIS QUESTION IS HERE: ifmandnarenegativeintegerswhatisthevalueofmn108394.html
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Re: If m and n are negative integers, what is the value of mn?
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