Is 100 in K?

[Sunshine85]

Q) K is a set of integers such 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.

The Answer is E.... But How?

[Vemuri]

I don't think the answer is E. It should be A. Let me explain.

The question stem says that if integer r is in K, then r+1 is also in K.

Stmt1: If 50 is in K, the 51 is also in K. If 51 is in K, then 52 is also in K.....and so on...until 99 is in K. If 99 is in K, then 100 also in K.......it goes on. So, this statement is sufficient to answer the question that 100 is in K.

Stmt2: If 150 is in K, the 151 is in K.......and so on upwards. This statement will not help us determine if 100 is in K. So, insufficient.[/b]

[Sunshine85]

Thanks Mr. Vemuri

[tdadic84]

vemuri,

But A does not mention how many integers are in K...what if it goes to 61 + 1 and then stops?? then 100 would not be in K, it does not tell us how many numbers are in the set...

am i missing something?

[splendentsky]

I think E is the answer because not enough information was given.

[Sunshine85]

Don u think if 50 is in K, 51 is in K?

if so 52 is also in K and this goes on.....

So I go with Vemuri.

Any further comments are welcome.

[DanaJ]

This topic has been discussed before. See Stuart's example for clarifications:

https://www.beatthegmat.com/ds-doubt-t35181.html

[criszerriny]

Keep in mind, the question is about a set of integers, so it must be A since B would make it infinite.