Gprep absolute value

[schumi_gmat]

y>=0, what is value of x?

1. mod(x-3) >=y
2. mod (x-3)<= -y

[spoiler]OA = B[/spoiler]

[logitech]

y>=0, what is value of x?

1. mod(x-3) >=y
2. mod (x-3)<= -y

[spoiler]OA = B[/spoiler]

This question needs an explanation, and that explanation is what the heck the MOD function is...Engineers will not have a problem with this question but rest of the people can wonder what MOD is:

The modulus function returns positive value of a variable or an expression. For this reason, this function is also referred as absolute value function. In reference to modulus of an independent variable, the function results in a non-negative value of the variable, irrespective of whether independent variable is positive or negative. [/i]


1. mod(x-3) >=y

|x-3| >= y.
x >= y+3

INSUF








2. mod (x-3)<= -y

|x-3|<=-y => y=0 Remember the mod function is non-negati

|x-3|=0

x=3

SUFF

Hence , B


[/i]

[schumi_gmat]

Thanks buddy

[cramya]

Any other approaches for statement II?

[maihuna]

somewhere I read people will try to fool you by |x| <= 0 it can at max be 0...nothing else...

[missrochelle]

Can someone explain why you set y= 0 in statment 2? Just because absolute value is non-negative, why do you set it to zero ?

[selango]

Absolute value of any integer is non negative (ie)greater or equal to zero.

If x is an integer |x|>=0


In stmt2,

mod (x-3)<= -y and y>=0

Let say y>0 and y=2

Then mod(x-3)<=-2-->mod(x-3) can be -2 or -1

But we know that absolute value is non negative.Then the above statement is invalid.

So what is the only possible value we can assume so that mod (x-3) is non negative?

We can solve this with Zero as mod(any integer)>=0

--> mod(x-3)=0

-->x=3

Hope this clarify!!!

[arora007]

y>=0, what is value of x?

1. mod(x-3) >=y
2. mod (x-3)<= -y

[spoiler]OA = B[/spoiler]

If you find these questions difficult.... try the MGMAT inequality tutorial...
they are wonderful...and are free...