If x is odd, all EXCEPT which one of the following must be odd?

Question

(A)  x^2 + 4x + 6 
(B)  x^3 + 5x + 3 
(C)  x^4 + 6x + 7 
(D)  x^5 + 7x + 1 
(E)  x^6 + 8x + 4

Chethan92 · Answer

Since x is odd.

Lets take x = 1.

Only option C is even. Rest all are odd.

C is the answer

Posted from my mobile device

PKN · Answer

To find:-All  EXCEPT  which one of the following must be odd?
 Implies that 4 incorrect answer options yield ODD output & one correct answer option yields EVEN output.

Three terms are there in each of the expressions in the answer options.

Note:-
1) An odd number in exponent form( Odd^{integer} ) is always odd.
2) Multiplication of odd numbers always yield odd number.
3) Multiplication of odd numbers by even numbers always yield even number.
A. O+E+E=O
B. O+O+O=O
 C. O+E+O=E 
D. O+O+O=O
E. O+E+E=O

Ans. (C)

varun4s · Answer

Put x=1 in the answer choice. All the options give odd result except C.

T1101 · Answer

Another way to look at this problem is to regognize that x^n will always be odd in all options. In A and E booth other terms are even, so A and E booth result in an odd number. In B and D booth other terms are odd, so B and D will booth result in an odd number.

Only option C has an even and odd term, and will therefore result in an even number. Hence C is the answer.

ScottTargetTestPrep · Answer

Recall that even x odd = even and odd x odd = odd. Let’s analyze each choice.

A) x^2 + 4x + 6

odd + even + even = odd

B) x^3 + 5x + 3

odd + odd + odd = odd

C) x^4 + 6x + 7

odd + even + odd = even

Answer: C

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If x is odd, all EXCEPT which one of the following must be odd?

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GMAT Problem Solving (PS) Questions

If x is odd, all EXCEPT which one of the following must be odd?

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