inequalities
This topic has expert replies
-
- Master | Next Rank: 500 Posts
- Posts: 135
- Joined: Mon Oct 03, 2011 6:54 am
- Followed by:4 members
If x > y, x < 6, and y> -3, what is the largest prime number that could be equal to x+ y?
GMAT/MBA Expert
- Anurag@Gurome
- GMAT Instructor
- Posts: 3835
- Joined: Fri Apr 02, 2010 10:00 pm
- Location: Milpitas, CA
- Thanked: 1854 times
- Followed by:523 members
- GMAT Score:770
-3 < y < x < 6nidhis.1408 wrote:If x > y, x < 6, and y> -3, what is the largest prime number that could be equal to x+ y?
As both x and y are less than 6, (x + y) must be less than 12.
Hence, the largest prime number that could be equal to (x + y) is the largest prime number number juts less than 12, i.e. 11.
This is possible for say, (x = 5.9 and y = 5.1) or (x = 5.6 and y = 5.4) etc.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)
Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)
Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
-
- Master | Next Rank: 500 Posts
- Posts: 101
- Joined: Sun Jun 03, 2012 10:10 pm
- Thanked: 10 times
- Followed by:1 members
Good Day Sir,
This was my way of solving the problem :
x < 6. So I considered x = 5
-3 < y < x. So y can be -3,-2,-1,0,1,2,3,4
From this max prime value of x + y = 7
To get x + y = 11, x needs to be 6 and y needs to be 5. But this is not possible as x < 6. Y cannot be 6 or more as y< x. So how can we get the sum as 11?
Please advise if there is a mistake in my understanding..
This was my way of solving the problem :
x < 6. So I considered x = 5
-3 < y < x. So y can be -3,-2,-1,0,1,2,3,4
From this max prime value of x + y = 7
To get x + y = 11, x needs to be 6 and y needs to be 5. But this is not possible as x < 6. Y cannot be 6 or more as y< x. So how can we get the sum as 11?
Please advise if there is a mistake in my understanding..
-
- Master | Next Rank: 500 Posts
- Posts: 101
- Joined: Sun Jun 03, 2012 10:10 pm
- Thanked: 10 times
- Followed by:1 members
- cypherskull
- Senior | Next Rank: 100 Posts
- Posts: 94
- Joined: Sat Mar 31, 2012 3:39 am
- Location: Calcutta
- Thanked: 8 times
From the problem statement, it can be deduced that -
-3< y < x <6.
The greatest value of x can be 5 which means y should then be less than 5.
Replacing the value of x as 5 in (x+y) and testing for the values of y < 5
5 + y (=4) => not prime
5 + y (=3) => not prime
5 + y (=2) => prime (Ans).
-3< y < x <6.
The greatest value of x can be 5 which means y should then be less than 5.
Replacing the value of x as 5 in (x+y) and testing for the values of y < 5
5 + y (=4) => not prime
5 + y (=3) => not prime
5 + y (=2) => prime (Ans).
Regards,
Sunit
________________________________
Kill all my demons..And my angels might die too!
Sunit
________________________________
Kill all my demons..And my angels might die too!
-
- Master | Next Rank: 500 Posts
- Posts: 462
- Joined: Wed Jan 19, 2011 1:08 pm
- Thanked: 10 times
- Followed by:4 members