Data Sufficiency

K is a set of integers sunch that if the integer r is in K, then r+1 is also in K. Is 100 in K?

(1) 50 is in k.
(2) 150 is in K.


ANS. (A)

I dont quite understand why knowing 50 is in K will help????

NS A

Stmt 1 - 50 is in the set K. So, as per the question, 51 will be in the same set.. Similarly 52 will be in the set. So on and So forth so 100 will be in the set.. SUFF

Stmt 2 - 150 is in the set K. It might be possible that 150 is the first element of the set so 100 cannot be in the set.. or it might be possible that the set is like 100, 101, .... 150.. So, 100 can or cannot be in the set. NOT SUFF

This is a cool question ...! Thnx for posting .!