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Is 100 in K?

Expert replies
by Sunshine85 » Sun May 10, 2009 1:53 am
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?
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Source: — Data Sufficiency |

Re: Is 100 in K?

by Vemuri » Sun May 10, 2009 5:04 am
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]
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by Sunshine85 » Sun May 10, 2009 8:52 pm
Thanks Mr. Vemuri
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by tdadic84 » Mon May 11, 2009 10:37 am
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?
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by splendentsky » Mon May 11, 2009 12:13 pm
I think E is the answer because not enough information was given.
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by Sunshine85 » Mon May 11, 2009 9:27 pm
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.
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by DanaJ » Tue May 12, 2009 2:37 am
This topic has been discussed before. See Stuart's example for clarifications:

https://www.beatthegmat.com/ds-doubt-t35181.html
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by criszerriny » Wed May 13, 2009 9:26 am
Keep in mind, the question is about a set of integers, so it must be A since B would make it infinite.
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