x and less than the integer y

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x and less than the integer y

by jain2016 » Fri May 06, 2016 9:21 pm
How many odd integers are greater than the integer x and less than the integer y ?

1) There are 12 even integers greater than x and less than y.

2) There are 24 even integers greater than x and less than y.

OAB

Hi Experts ,

Please explain.

Many thanks in advance.

SJ
Last edited by jain2016 on Sun May 22, 2016 3:56 am, edited 1 time in total.
Source: — Data Sufficiency |

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by GMATGuruNY » Fri May 06, 2016 9:29 pm
The posted problem has been transcribed incorrectly.
In the version above, the two statements contradict each other:
If there are a total of 12 integers between x and y (statement 1 above), then there cannot be a total of 24 even integers between x and y (statement 2 above).
On the GMAT, the two statements will never contradict each other.
The original problem is from GMATPrep.
In the GMATPrep version, the two statements read as follows:
How many odd integers are greater than integer X and less than the integer y?
1. There are 12 even integers greater than x and less than y
2. There are 24 integers greater than X and less than Y
jain2106, please edit your post accordingly.

Statement 1: There are 12 even integers greater than x and less than y.
Let the 12 consecutive even integers greater than x and less than y be the following:
0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22.
Here, x<0 and y>22.
If x=-1 and y=23, then every odd integer between 1 and 21, inclusive, will be greater than x and less than y, for a total of 11 odd integers.
If x=-1 and y=24, then every odd integer between 1 and 23, inclusive, will be greater than x and less than y, for a total of 12 odd integers.
INSUFFICIENT.

Statement 2: There are 24 integers greater than x and less than y.
EXACTLY HALF of these 24 consecutive integers must be odd.
Thus, the number of odd integers greater than x and less than y = 12.
SUFFICIENT.

The correct answer is B.
Last edited by GMATGuruNY on Sat May 07, 2016 3:01 am, edited 2 times in total.
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by jain2016 » Fri May 06, 2016 10:56 pm
Statement 1: There are 12 even integers greater than x and less than y.
Let the 12 consecutive even integers greater than x and less than y be the following:
0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22.
Here, x<0 and y>22.
If x=-1 and y=23, then every odd integer between 1 and 21, inclusive, will be greater than x and less than y, for a total of 11 odd integers.
If x=-1 and y=24, then every odd integer between 1 and 23, inclusive, will be greater than x and less than y, for a total of 12 odd integers.
INSUFFICIENT.

Statement 2: There are 24 integers greater than x and less than y.
EXACTLY HALF of these 24 consecutive integers must be odd.
Thus, the number of odd integers greater than x and less than y = 12.
SUFFICIENT.

The correct answer is B.
[/quote]

Hi GMATGuruNY ,

Can you please explain more. I didn't get this.

Please explain sir.

Many thanks in advance.

SJ

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by nchaswal » Fri May 06, 2016 11:10 pm
GMATGuruNY wrote:
How many odd integers are greater than integer X and less than the integer y?
1. There are 12 even integers greater than x and less than y
2. there are 24 integers greater than X and less than Y
Statement 1: There are 12 even integers greater than x and less than y.
Let the 12 consecutive even integers greater than x and less than y be the following:
0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22.
...
,
,
,
,
SUFFICIENT.

The correct answer is B.
Hi I am confused that how the question which SJ posted got copied differently in your post? He posted

</b>How many odd integers are greater than the integer x and less than the integer y ?

1) There are 12 integers greater than x and less than y.

2) There are 24 even integers greater than x and less than y. </b>

If what he posted is true then answer has to be A not B.. But SJ you need to check what is actually written in the question.
For statement 1 is it 12 INTEGERS only or 12 EVEN INTEGERS which somehow appears on GMATGuru's post but not yours and likewise for Statement 2.

Also it is a good practice to not post the answer beforehand. Let people try and revert and then you can check the answer. The spoiler system is effective but should not be used right away by someone who is posting the question.

Regards
Nits
It is GMAT. So what?

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by GMATGuruNY » Sat May 07, 2016 2:59 am
nchaswal wrote:Hi I am confused that how the question which SJ posted got copied differently in your post?
Good catch.
To my solution above, I've added the following:
The posted problem has been transcribed incorrectly.
In the version above, the two statements contradict each other:
If there are a total of 12 integers between x and y (statement 1 above), then there cannot be a total of 24 even integers between x and y (statement 2 above).
On the GMAT, the two statements will never contradict each other.
The original problem is from GMATPrep.
In the GMATPrep version, the two statements read as follows:
Quote:
How many odd integers are greater than integer X and less than the integer y?
1. There are 12 even integers greater than x and less than y
2. There are 24 integers greater than X and less than Y
jain2106, please edit your post accordingly.
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by [email protected] » Sat May 07, 2016 9:20 am
Hi jain2016,

This DS question is ultimately a test of your 'thoroughness'; you can TEST VALUES to answer it, but you have to make sure that you consider that the first example that you come up with might not be the only answer to the question...

We're told that X and Y are INTEGERS. We're asked for the number of ODD integers that are greater than X and less than Y.

1) There are 12 EVEN integers greater than X and less than Y

IF....
X = 0
Then the 12 EVEN integers would be...
2,4,6,8,10
12,14,16,18,20
22,24
Y could actually be 2 DIFFERENT values though: 25 OR 26

IF....
Y = 25
Then the ODD integers between 0 and 25 are....
1,3,5,7,9
11,13,15,17,19
21,23
For a total of 12 odd integers

IIF....
Y = 26
Then the ODD integers between 0 and 26 include 1 EXTRA INTEGER....
1,3,5,7,9
11,13,15,17,19
21,23,25
For a total of 13 odd integers
Fact 1 is INSUFFICIENT

2) There are 24 INTEGERS greater than X and less than Y.

Without the restriction of 'odd' or 'even', the work becomes a lot easier (it's ultimately a Number Property). With 24 CONSECUTIVE integers, half will be odd (12 terms) and half will be even (12 terms) - that will never change. For example....

IF....
X = 0
Then the 24 values would be 1-24 (inclusive) and Y could only be one value...
Y = 25

From our prior work, we know that that answer to the question is 12.
Fact 2 is SUFFICIENT

Final Answer: B

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