data sufficiency.

ssrege wrote:data sufficieny question:

is x>2? (you may assume that y is not equal to zero)

(a) (x/y) is greater than 2.

(b) (1/y) is less than 1.


Apart from solving this question, I want to know if (1/y) < 1, also means y<1. I dont know when do we change the greater than or less than sign

(a) (x/y) is greater than 2.

both x and y are positive or
both x and y are negative

x=6 y=2 x>2 true
x=-6 y=-2 x>2 false

not sufficient

(b) (1/y) is less than 1.

x can be any value.. >2 or <2
not suffcient

combined

same as (A)

x=6 y=2 1/y<1 -->x>2 true
x=-6 y=-2 1/y<1 --> x>2 false

not sufficient

E.

Apart from solving this question, I want to know if (1/y) < 1, also means y<1. I dont know when do we change the greater than or less than sign

No. need not be be the same.

take below example

5 > 2
when you multiply on both sides with -ve number sing will change
multiple (-1) on both sides
-5<-2
when you multiple on both sides with +ve number then sign will not change
multipl with 2
10>4

I hope it is clear.