8)

Amazingly tricky! Gmat's def getting hard

Anyways, here it goes

1) (K+1)^3 = (k+1)^2 * (k+1)
= k3 + k2 + 2k2+2k+k+1

So, the question is basically asking you the remainder for
(k3 + k2 + 2k2+2k+k+1)/k

so if you divide this by k, you'll be left with 1/K as the only thing that is not divisible by K and since K>1, the remainder shall always be one (1/2 - remainder =1 ; 1/192302 - remainder always 1).

It took me a couple of minutes to fig this out.

2) K=5 tells us nothing.

Though even if you dint figure out statement 1 -why did you pick E - with the info given in B added to the info given in A - you could have found the answer. C would have been a better guess.

9)

Let the lines be y1 = m1x1 + c1
and y2 = m2x2 + c2

from A :
(-c1/m1) * (-c2/m2) >0 - insufficient

From B
C1*C2 <0 - Insufficient

From A and B

let P = C1*C2 - we know P<0
so statement A becomes P/(m1*m2)>0 - so m1*m2 has to be >0 for this equation to hold.

Let me know if this helps.