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
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
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
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.

130-point 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.

Medium level - sequence II

Expert replies
by Brent@GMATPrepNow » Thu Mar 05, 2009 1:27 pm
Image

Please note that this is not an official GMAT question; it’s my attempt to create mid-range (500 to 650-level) GMAT-style questions for this forum.
Brent Hanneson - Creator of GMATPrepNow.com
Image
Join the discussion
Source: — Problem Solving |

by truplayer256 » Thu Mar 05, 2009 2:32 pm
The above sequence is a geometric sequence. Therefore:

a1r^n-1 is equal to the nth term of the sequence. R is the common ratio of each of the preceding terms, which in this case is 2.

20th term=1(2)^19
21st term=1(2)^20
22nd term=1(2)^21

2^19+2^20+2^21=2^19(1+2+2^2)=7 * 2^19 B
Join the discussion

by Brent@GMATPrepNow » Thu Mar 05, 2009 2:41 pm
Nice work - the answer is B
Here's my solution as well.

Image
Brent Hanneson - Creator of GMATPrepNow.com
Image
Join the discussion