is X odd if X^3 is odd??

zealzoom wrote:Hi ,

Do let me know if this is sufficient to answer the question,,,

Is X odd ??

X^3 is Odd,,,,

Cheers
zeal

Yes it is sufficient.

Assuming X is an integer (positive or negative)

X^3 can only be odd if X itself is odd

because Odd times Odd is Odd

Even times Anything is Even.

naah thats the catch here!!!

I also think in the same way and this question seems very easy to me..

Here is the situation..

What if X = cube root 7 or cube root 3 ?? then X^3 will be odd but X itself is not an integer rather, it is an irrational number so no chance we cam certainly say that X is ODD,,,

Oh boy !! this line of reasoning really freaked me out.. let me know how do you feel ??

theses nothing wrong in zipper s reply.

he's right. because he assumed that X is an integer.
so technically given condition is not sufficient. we need to know whether X is am integer or not.

pls present the full problem.

that was the problem

is X odd

a) 2x-1 is odd

b) X^3 is odd ..

My answer was B and i was pretty sure about that, but correct answer was E and reason I have already given.

DS,, its real tough to get into it ,,,

Any help??

Zeal

where did this question come from?

zealzoom wrote:that was the problem

is X odd

a) 2x-1 is odd

b) X^3 is odd ..

My answer was B and i was pretty sure about that, but correct answer was E and reason I have already given.

DS,, its real tough to get into it ,,,

Any help??

Zeal

Even I feel B is right answer... for a product to be even, atleast one of the integers must be even. So if both integers are odd then the product remains odd. For x^3 to be odd, all 3 should be odd... so x has to be odd.

800guy wrote:where did this question come from?

this was question in Kaplan GMAT test ....