If x is a non-negative integer then find x?(Source:GMATINSIG

[GMATinsight]

If x is a Non-Negative integer then find x?
(1) x^2−5x+6=0
(2) x^2=3x

(Source:www.GMATinsight.com)

Answer: option C

[melguy]

1) x^2-5x+6=0
(x-3) (x-2) = 0
x = 3 or x = 2
Not Sufficient

2) x^2=3x
Divide both sides by x
x = 3
Sufficient

[GMATinsight]

1) x^2-5x+6=0
(x-3) (x-2) = 0
x = 3 or x = 2
Not Sufficient

2) x^2=3x
Divide both sides by x
x = 3
Sufficient

You answer is Incorrect because of a small mistake that you have made while solving the second statement

x^2=3x
You CAN'T divide both sides by x because x may be zero as well. You can only divide an equation by a variable when you know it's non zero

therefore, x^2=3x
i.e. x^2-3x = 0
i.e. x (x-3) = 0
i.e. x = 0 or 3 i.e.
NOT SUFFICIENT

Combining both statements
x=3
SUFFICIENT

Answer: Option C

[Brent@GMATPrepNow]

NOTE: when we're told that a number is "non-negative," we must be careful not to conclude that the number is positive.
A non-negative number can be positive or it can equal 0

Cheers,
Brent

[melguy]

NOTE: when we're told that a number is "non-negative," we must be careful not to conclude that the number is positive.
A non-negative number can be positive or it can equal 0

Cheers,
Brent

My bad!
Thanks for correcting me.