NUMBER PROPERTIES

[SRIRAM.ITECH]

HI
I have a doubt in the answer of the below question
I found this question in the Manhattan prep " NUMBER PROPERTIES "

QUES: If x²/4 is an integer greater than 50, then what is the smallest possible value for x² ?
ANS GIVEN WAS - 256

My question how it is 256...i thought the answer was 204.....and got confused with this........its states that x²/4 is an integer ( not x ).... please help me out

THANKS

[gbd97]

hi ,
which version you are using?? 2nd or 3rd??
i concur with you....
x² is integer not necessarily x ..may be someone from official could clarify us.

[SRIRAM.ITECH]

hi ,
which version you are using?? 2nd or 3rd??
i concur with you....
x² is integer not necessarily x ..may be someone from official could clarify us.

I am using 3rd edition books......

[navigalactus]

Lets have a look at the possible options that will make this a perfect square, and at the same time, divisible by 4.



This should help

-Navi

[gbd97]

navi you are correct if x is integer

btw.....i checked the errata of third edition...
they corrected it and it is assumed that x is also integer which is not included in the question.

[navigalactus]

Even if we factor Z in terms of x and y, then also we can't get an Integer, as specified by the question.

[gbd97]

well you misunderstood me.....
if x is integer than the answer is 256
if x is not integer( which is not mentioned in the book) than the answer is 204

[navigalactus]

[tommywallach]

Hey Guys,

Navi, there's no need to get rude at people. Indeed, the question as originally written is incorrect. You have to assume that x itself is an integer to get that answer, and it would have been a legitimate question without that constraint. For example, the question could have been testing to see if you accidentally ASSUMED that x was an integer, even though the question didn't state it, in which case Navi's explanation would actually be falling for the trap, because the correct answer would be 204, as opposed to 256.

In short, try to only study with the most recent versions of our books. Mistakes happen!

Oh, and keep it friendly on the forums! : )

-t

[navigalactus]

Hey Tommy,
Sorry for my post in that manner that was in response to the inappropriate statement that was later edited by the user.
Thanks for the clarification, I ruled out x as a fraction but missed where x can be a fraction exponent where


Thanks again :)

[tommywallach]

No worries at all. I didn't notice that things had been edited out! :)

-t