GMAT Data Sufficiency (DS) | If x, y and z are integers, is x – y greater than y – z?

Hi,

it asks whether x-y>y-z ----> or x+z>2y ?

st1. states that x>z we can infer x+z>z+z with this we can rewrite question whether 2z>2y or simply z>y? as we don't know. insuff.

st2. it states z>y and we can rewrite the question whether x>y? no info therefore insuff.

st1+2. from 1 we arrive to whether z>y ? and 2 states that z>y therefore it is sufficient.
C

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