If n is an integer, is -3x^n positive?
A. x is odd
B. n is odd
Answer is C
Please explain why A is not the answer?
Thanks again!!
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If n is an integer....? Help Please!!
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Anurag@Gurome
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gmatpup wrote:If n is an integer, is -3x^n positive?
A. x is odd
B. n is odd
Answer is C
Please explain why A is not the answer?
Thanks again!!
(1) If x = 1 (odd), n = 1 (odd) then -3x^n = -3(1)^1 = negative.
If x = -1 (odd), n = 1 (odd) then -3x^n = -3(-1)^(1) = positive.
No definite answer; NOT sufficient.
(2) Again taking the same examples as in statement 1, we know (2) is also NOT sufficient.
Combining (1) and (2) also, taking the same examples as in 1, we do not know if -3x^n is positive or not; NOT sufficient.
According to me the answer should be E, can you please check it?
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neelgandham
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If n is an integer, is -3x^n positive?
If x = -3 and if n = 4, -3x^n is Negative
If x = 3 and if n = 3, -3x^n is Negative
If x = 3 and if n = 4, -3x^n is Negative
If x = -3 and if n = 3, -3x^n is Positive
If x = 3 and if n = 3, -3x^n is Negative
If x = 0 and if n = 3, -3x^n is Neither positive, nor negative
From A and B, x is odd and n is odd.
If x = -3 and if n = 3, -3x^n is Positive
If x = 3 and if n = 3, -3x^n is Negative
IMO E. As Anurag requested, Can you please check ?
If x = -3 and if n = 3, -3x^n is PositiveA. x is odd
If x = -3 and if n = 4, -3x^n is Negative
If x = 3 and if n = 3, -3x^n is Negative
If x = 3 and if n = 4, -3x^n is Negative
B. n is odd
If x = -3 and if n = 3, -3x^n is Positive
If x = 3 and if n = 3, -3x^n is Negative
If x = 0 and if n = 3, -3x^n is Neither positive, nor negative
From A and B, x is odd and n is odd.
If x = -3 and if n = 3, -3x^n is Positive
If x = 3 and if n = 3, -3x^n is Negative
IMO E. As Anurag requested, Can you please check ?
Anil Gandham
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LalaB
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hm, may be in A option it is said x is negative?gmatpup wrote:If n is an integer, is -3x^n positive?
A. x is odd
B. n is odd
Answer is C
Please explain why A is not the answer?
Thanks again!!
it would be better
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pemdas
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yes, please check the source
restate -x^n positive?
n is integer
st(1) x is odd, implies x cannot be 0 and following
- positive x returns negative number when n is odd/even;
- negative x returns positive number when n is odd and returns negative number when n is even;
Not Sufficient
st(2) n is odd, implies only power and without x this is Not Sufficient
Combined st(1&2): if x>0 and odd (st.1)along with n is odd (st.2) -3x^n is negative.
If x<0 and odd (st.1)along with n is odd (st.2) -3x^n is positive.
Not Sufficient
restate -x^n positive?
n is integer
st(1) x is odd, implies x cannot be 0 and following
- positive x returns negative number when n is odd/even;
- negative x returns positive number when n is odd and returns negative number when n is even;
Not Sufficient
st(2) n is odd, implies only power and without x this is Not Sufficient
Combined st(1&2): if x>0 and odd (st.1)along with n is odd (st.2) -3x^n is negative.
If x<0 and odd (st.1)along with n is odd (st.2) -3x^n is positive.
Not Sufficient
gmatpup wrote:If n is an integer, is -3x^n positive?
A. x is odd
B. n is odd
Answer is C
Please explain why A is not the answer?
Thanks again!!
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CollegeKart
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i agree with Anurag. With the given information the answer should be E
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arpan20690
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amit28it
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Hello buddy,
Sorry to be here but can anyone suggest me to solve my typical questions related to Decimals for Grade IV . So please help me .
Sorry to be here but can anyone suggest me to solve my typical questions related to Decimals for Grade IV . So please help me .
