NUmber properties guide page 78

[Sundeep]

I have a question about the the second statement for the question on this page (in BOLD).
If x is a positive integer, is x^3-3x^2+2x divisible by 4
this simplified => x(x-1)(x-2)
I understand how statement 1 is sufficient but

statement 2 is
x=2z+2, where z is an integer
if we assume z =0
we get x = 2
then how is 2x1x0 divisible by 4
what am i missing here
that gets us to the answer D that 2 is also sufficient

[Brijesh Singh]

Dear Sundeep,

Let me try expanding the equation, i found this method doesn't require any logic

- stmt(2) x = 2(z+1)

Put in the actual question => x (x-1) (x-2) / 4
=>2 (z+1) (2z +1 ) (2z) / 4
=>2*2 (z+1) (2z+1) (z) /4
=>(4/4) ((z+1) (2z+1) (z))
=> ((z+1) (2z+1) (z)) is integer as z is int....

Best regards
Brijesh

[sundeep]

I understand what you did.
what i was trying to get was is 0 divisible by 4 or not...
For me it is but I am not sure if GMAT thinks the same way or not...
I am going to take it that 0 is divisible by 4 and go from there...
please let me know if I am wrong though

[StaceyKoprince]

0 is, in fact, divisible by 4. 0 is divisible by everything (except 0 - and they don't test that on the test). Let us know if you still have a question!