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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
Vote for Target Test Prep, Newsweek Readers’ Choice Awards 2026
NEWSWEEK READERS’ CHOICE 2026

BIG NEWS! Target Test Prep has been nominated, and they’d love your vote!

TTP has worked incredibly hard to build the best test prep experience possible, and winning Newsweek’s 2026 Readers’ Choice Award for Best Test Prep would mean a lot to them. If TTP has helped you, they’d be incredibly grateful for your vote. You can vote once each day through September 9.

Vote for TTP
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

OG Green Book Question

Expert replies
by ket » Wed Aug 12, 2009 11:25 am
IF w+z=28 what is the value of wz?

(1) w and z are positive integers
(2) w and z are consecutive odd integers

I solved this problem by plugging in numbers and got the correct answerB

But my problem is this... the OG Book has an explanation like this:
'to look at this problem more formally, let the consecutive odd integers w and z be represented 2n+1 and 2n+3, where n is any integer. The equation in the problem can thus be expressed as... w+z= (2n+1) + (2n+3) and solved for n the result is w=2X6+1=13 and z=2X6+3=15, " i.e. B is sufficient.

What I don't understand here is that how come 2n+1 and 2n+3 express
consecutive odd integers? Because for instance 7 and 11 are consecutive odd integers but they cannot be expressed as 2n+1 and 2n+3...

I am confused, can someone explain why OG explanation is correct?


Thanks a lot
Join the discussion
Source: — Data Sufficiency |

by ashis979 » Wed Aug 12, 2009 11:42 am
OG explanation is fine.

2n is an even integer for any integer value of n. Therefore, 2n+1, 2n+3, 2n+5, and so on have to be consecutive odd integers.

7 and 11 are consecutive prime numbers NOT consecutive odd integers. It's 7 and 9. So when n=3, 2n+1=7 and 2n+3=9.

2n+1+2n+3=28 => 4n=24 => n=6
So, 2n+1=13 and 2n+3=15 => 13+15=28. So, B alone is SUFFICIENT
Join the discussion

by ket » Wed Aug 12, 2009 11:54 am
ashis979 wrote:OG explanation is fine.

2n is an even integer for any integer value of n. Therefore, 2n+1, 2n+3, 2n+5, and so on have to be consecutive odd integers.

7 and 11 are consecutive prime numbers NOT consecutive odd integers. It's 7 and 9. So when n=3, 2n+1=7 and 2n+3=9.

2n+1+2n+3=28 => 4n=24 => n=6
So, 2n+1=13 and 2n+3=15 => 13+15=28. So, B alone is SUFFICIENT
Thanks ashis979... I really missed the part that 7 and 11 are consecutive prime integers not odd ones :)
Join the discussion