E for me ,

1) X^2 is positive therefor x can be positive or negative

2) x.|y| is not a postive number , thus x can be 0 , -ve or +ve

it can be positive when |y| = 0,

combining X CAN BE +VE , -VE , thus E

it should be B ,
A is not sufficient ....because its not mentioned whether travel left at the schedule time

should be E We need to find if y>1.5 z first statement says y>0.66 Z , clearly insufficient because if y >0.66 z it can or cannot be greater than 1.5 z 2nd statement says y<2z, again insufficient because if y <2z it can or cannot be greater than 1.5 z combined 0.66z<y<2z again y can be greater than ...

A it ,

n = (k-1)k(k+1)
implies product of 3 consecutive numbers , which will always be divisible by 6

yes gmat009 , B is sufficient too
thanks for the explanation...

it should be D

D it is ,

we knw x >0 , thus x^2 will be less than x when 0<x<1

first statement says this only x is a fraction


2nd x^3 <x^2 , again this will happen only when x is a fraction
thus x^2 will be less than x

Looks to be E

no actually I wanted to knw hw B is insufficient,

i.e z^2 = x^2+y^2 ,
it seems to me this is sufficient to prove that
x>z-y

e.g z= 13, y = 12, x =5
z= 13 , y = 12, x = 5

I cant find a case where the condition is insufficient