Interesting DS question

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by breakkgmat » Tue Jul 26, 2011 2:31 pm
Its D..Just uae any value of Y & Z in the equation & you will find that it is divisible by 4.

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by prateek_guy2004 » Mon Aug 01, 2011 10:46 am
Without even solving it one should understand that in 1 st equation its +2 which is a divisible of 4 and second statement too is a div of 4. so answer is D.

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by anshulinpc1 » Tue Aug 09, 2011 6:04 pm
I think the answer is A. because it says x >0

and using the 1st option -> x=4y+4, we have to make sure we put such a value y that makes x >0. So if we put y = -1 then x = -4+4 = 0 so y=-1 is an invalid choice.
Let us try with y = 0, then x = 4 -- divisible by 4. and as in this equation we are adding it with an even number and multiplying by 4 so the result will always be even. Putting x=4 in the main equation
-> 64-48+8 = 24, divisible by 4.

Option 2 - The same rule applies here. We can not assume z to be -1, that will make x as 0. so let us try with 0. that will give us x = 2 and putting it in the main equation - 8-12+4 =0 which is not divisible by 4. So the answer should be A.

Thanks.
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by codytravers » Mon Aug 15, 2011 12:13 pm
I agree... even though the OA is apparently D, can anyone find fault with anshul's explanation of the problem?

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by pm » Sun Aug 21, 2011 1:04 pm
The Fault with Anshul Explanantion is :

Stacey Comment :
FYI: the term divisible, or evenly divisible, means that there is no remainder when solving. Zero divided by anything but zero equals zero. No remainder - so zero is, in fact, divisible by 4 (or anything except zero). Zero divided by zero is undefined.

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by AbhiJ » Mon Aug 22, 2011 4:17 am
Its much easier if we factorise the initial expression to x(x-1)(x-2)

A.) Now when x = 4y + 4 , the expression is divisible by 4 as x is divisible by 4.

B.) Now when x = 2z + 2, then the expression is (2z+2)(2z+1)2z
Again this is equal to 4(z+1)(2z+1)(z), which is divisible by 4.

Hence D is the answer.

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by sl750 » Mon Aug 22, 2011 10:13 am
I agree, answer is D

Both statement 1 and 2 provide us with two factors of 2, which makes it divisible by 4. The original prompt can be simplified as a consecutive product, as, x(x-1)(x-2)

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by prashant misra » Wed Sep 28, 2011 5:35 am
my official answer is D i got it right just picked some values which satisfy both statements

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by RAMYAMUR » Mon Oct 03, 2011 4:06 am
If x > 0, then is x^3 - 3(x^2) + 2x divisible by 4?

1. x = 4y + 4, where y is an integer
2. x = 2z + 2, where z is an integer

---------------

1. x= 4(y+1) implies x is divisible by 4.
x^3 - 3x^2 +2x = x(x^2-3x+2) = 4(y+1)(x^2-3x+2). Statement 1 is sufficient

2. x = 2(z+1)
x^3 - 3x^2 +2x = 2.2.2(z+1)^3 - 3.2.2(z+1)^2 + 2.2(Z+1). Statement 2 is also sufficient

Ans : D

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by dipper » Mon Oct 10, 2011 10:14 am
I got D as the answer choice by simplifying the equation to x(x-2)(x-1). For each data, I plugged in numbers to see if x(x-2)(x-1) was divisible by 4. Is this the fastest way to get to the answer?

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by parul9 » Thu Oct 20, 2011 9:18 am
It is D.
I did it by substitution of numbers. But I think I took more time that I should have.

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by neelgandham » Fri Oct 21, 2011 1:36 am
codytravers wrote:I agree... even though the OA is apparently D, can anyone find fault with anshul's explanation of the problem?
0 is divisible by any number except 0 and the result is 0. Not happy with what you see ?

ok 0/k = 0*(1/k) = 0 * real number = ? 0 !
Anil Gandham
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by immaculatesahai » Sun Dec 18, 2011 12:13 am
D it is. Factorize the expression to remove any ambiguity.

You will get (x-2)(x-1)(x)/4

Hence all we need to know is that x is even.

Both statements address the issue.

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by Sharma_Gaurav » Mon Jan 09, 2012 1:22 pm
straight D, easy

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by [email protected] » Sun Jan 22, 2012 4:18 am
Guyz according to me the answer is D for this DS quesion.

If x>0, then is x^3-3x^2+2x divisible by 4?

1. x=4y+4 where y is an integer
2. x=2z+2; were z is an integer

So the values for y and z should be > 0 and only intergers, when u put in values you get x divisible by 4.

Hence D...
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