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

Redeem

can somebody please help with this problem

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Quantitative Reasoning |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 511
Joined: Wed Aug 11, 2010 9:47 am
Location: Delhi, India
Thanked: 344 times
Followed by:86 members

by Anju@Gurome » Sun Apr 07, 2013 9:59 am
amandeep.hora wrote:If -13 < 7a + 1 < 29 and 19 < 2 - b < 23, what is the maximum possible integer value of a + b?
-13 < 7a + 1 < 29 ---> -14 < 7a < 28 ---> -2 < a < 4
19 < 2 - b < 23 ---> 17 < -b < 21 ---> -21 < b < -17

Hence, (a + b) < 4 + (-17) ---> (a + b) < -13

Maximum possible integral value of (a + b) is -14
Anju Agarwal
Quant Expert, Gurome

Backup Methods : General guide on plugging, estimation etc.
Wavy Curve Method : Solving complex inequalities in a matter of seconds.

§ GMAT with Gurome § Admissions with Gurome § Career Advising with Gurome §
Top
User avatar
Senior | Next Rank: 100 Posts
Posts: 31
Joined: Sun Jul 12, 2009 10:11 am
Thanked: 1 times

by amandeep.hora » Sun Apr 07, 2013 1:37 pm
thanks for taking the time to reply Anju !!

I still have a doubt though ,

I followed the below steps
-13 < 7a + 1 < 29 ---> -14 < 7a < 28 ---> -2 < a < 4
19 < 2 - b < 23 ---> 17 < -b < 21 ---> -21 < b < -17

then I chose -16 as the highest value that b can have and +3 highest integer value that a can have then their sum comes as -13 .

Still wondering what is wrong in my approach

really appreciate your help

Cheers,
Aman
Regards
Aman
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Mon Apr 08, 2013 5:13 am
amandeep.hora wrote:thanks for taking the time to reply Anju !!

I still have a doubt though ,

I followed the below steps
-13 < 7a + 1 < 29 ---> -14 < 7a < 28 ---> -2 < a < 4
19 < 2 - b < 23 ---> 17 < -b < 21 ---> -21 < b < -17

then I chose -16 as the highest value that b can have and +3 highest integer value that a can have then their sum comes as -13 .

Still wondering what is wrong in my approach

really appreciate your help

Cheers,
Aman
First, the question doesn't say that a and b are integers. It says that a+b is an integer.
Second, if -21 < b < -17, then b cannot equal -16

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Post new topic Post Reply
• Page 1 of 1