BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

DS: ODD integers

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 12
Joined: Tue Dec 15, 2015 12:35 am

DS: ODD integers

by romitrock » Sun Jan 17, 2016 7:31 am
Q: How many odd integers are greater than integer x and less than integer y?

st1: there are 12 even integers between x and y.
st2: there are 24 integers between x and y.
Top
Source: — Data Sufficiency |
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Sun Jan 17, 2016 7:39 am
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.
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.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Junior | Next Rank: 30 Posts
Posts: 12
Joined: Tue Dec 15, 2015 12:35 am

by romitrock » Sun Jan 17, 2016 8:50 am
yes Mitch i agree with this solution, but in the actual question they havent anything about the integers being consecutive.
that is why i posted this.
this is a question from the Gmat prep practice test 1.[/quote]
Top
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Sun Jan 17, 2016 9:51 am
romitrock wrote:yes Mitch i agree with this solution, but in the actual question they havent anything about the integers being consecutive.
that is why i posted this.
this is a question from the Gmat prep practice test 1.
Statement 1: There are 12 even integers greater than x and less than y.
If we select 12 NON-consecutive even integers to place between x and y, then there will be MORE THAN 12 even integers greater than x and less then y.
Consider the following case:
0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 24.
Here, the 12 even integers are consecutive except for the last two.
If x=-1 and y=25, then the following even integers will be greater than x and less than y:
0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24.
The result is 13 even integers between x and y.
Implication:
For statement 1 to be satisfied, the 12 even integers selected MUST be consecutive.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Junior | Next Rank: 30 Posts
Posts: 12
Joined: Tue Dec 15, 2015 12:35 am

by romitrock » Mon Jan 18, 2016 11:20 am
THANKS Mitch,

i had the impression that if we have to choose 12 even integers between x and y, we can choose infinite no. of integers depending on the values of x and y , if the nos. are not to be consecutive.
so in a way it is implied that the integers should be consecutive.
so it was a trick kind of thing in the question which needs to be identified.

I thought it isn't mentioned in the question so i should not consider it on my own.
Top
Post new topic Post Reply
• Page 1 of 1