Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Nov 2007:30 AM PST
-08:30 AM PST
Learn what truly sets the UC Riverside MBA apart and how it helps in your professional growth
Nov 2211:00 AM IST
-01:00 PM IST
Do RC/MSR passages scare you? e-GMAT is conducting a masterclass to help you learn – Learn effective reading strategies Tackle difficult RC & MSR with confidence Excel in timed test environment- Nov 23
11:00 AM IST
-01:00 PM IST
Attend this free GMAT Algebra Webinar and learn how to master the most challenging Inequalities and Absolute Value problems with ease. 
Nov 2510:00 AM EST
-11:00 AM EST
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors.
03 Sep 2018, 05:51
Kudos
Bookmarks
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
55%
(hard)
Question Stats:
57% (02:09) correct
43%
(01:06)
wrong
based on 21
sessions
History
Date
Time
Result
Not Attempted Yet
If AB is a tangent to the circle above, what is ∠ACD?
(1) DE is a diameter
(2) ∠CDE = ∠CED
03 Sep 2018, 05:52
Kudos
Bookmarks
Official Solution:
We’ll go for ALTERNATIVE since we can play with the figure to eliminate the wrong answers.
(1) ∠ECD is an inscribed angle facing a diameter, meaning that it equals 90°, but moving point D closer to or farther from point C shows us that the size of ∠ACD can change – not enough! (A) and (D) are eliminated.
(2) The two equal angles mean that the triangle is an isosceles. This means that, due to symmetry, ∠ACD = ∠BCE − but that’s not enough in order to determine their size. (B) is eliminated.
If we combine the two statements, ∠ACD + ∠BCE = 90˚, and since they are both equal, each of them is 45˚ − that’s enough! (E) is eliminated.
Answer: C
We’ll go for ALTERNATIVE since we can play with the figure to eliminate the wrong answers.
(1) ∠ECD is an inscribed angle facing a diameter, meaning that it equals 90°, but moving point D closer to or farther from point C shows us that the size of ∠ACD can change – not enough! (A) and (D) are eliminated.
(2) The two equal angles mean that the triangle is an isosceles. This means that, due to symmetry, ∠ACD = ∠BCE − but that’s not enough in order to determine their size. (B) is eliminated.
If we combine the two statements, ∠ACD + ∠BCE = 90˚, and since they are both equal, each of them is 45˚ − that’s enough! (E) is eliminated.
Answer: C
13 Sep 2018, 18:20
Kudos
Bookmarks
Bunuel
Hi Bunuel,
What do you mean by moving point D closer to or farther from point C? if DE is the diameter and C is in the tangent shoulnd't both angles be the same? I mean, doesn't statement 1 give enough evidence to conclude what statement 2 says?
thanks!
