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.

In the figure shown. point O is the center of the semicircle

Expert replies
Source: — Data Sufficiency |

IMO C

by agoyal2 » Sun Nov 30, 2008 12:16 am
IMO C:

Isosceles triangles with two sides = Radius

Angle BOA = Angle BAO
Angle BCO = Angle CBO

From 1: Angle COD = 60.
From 2: Angle BCO = 40 => Angle COB = 100

Angle BAO = Angle BOA = 180-60-100=20

Whats the OA?
Join the discussion

by mals24 » Sun Nov 30, 2008 4:55 am
Ok there are 2 concepts of a triangle that are applied to this question.
1. exterior angle theorem: An exterior angle of a triangle is equal to the sum of the opposite interior angles.
2. opposite sides of equal angles are also equal.

Given in the question:

OC=OB=AB. BAO = ?

St 1: COD = 60

BAO+BCO = 60 (Exterior angle theorem)

BCO = OBC

BAO+OBC = 60

BAO+BOA = OBC (exterior angle theorem)
BAO = BOA

2BAO = OBC

3BAO = 60
BAO = 20....SUFF

ST 2 BCO = 40
BCO = OBC
2BAO = OBC
BAO = 20....SUFF

Answer is D.
Join the discussion