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 2001:30 PM EST
-02:30 PM IST
Learn how Kamakshi achieved a GMAT 675 with an impressive 96th %ile in Data Insights. Discover the unique methods and exam strategies that helped her excel in DI along with other sections for a balanced and high score.
Nov 1912:30 PM EST
-01:30 PM EST
Learn how Keshav, a Chartered Accountant, scored an impressive 705 on GMAT in just 30 days with GMATWhiz's expert guidance. In this video, he shares preparation tips and strategies that worked for him, including the mock, time management, and more
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 2407:00 PM PST
-08:00 PM PST
Full-length FE mock with insightful analytics, weakness diagnosis, and video explanations!
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 Jul 2018, 11:15
Kudos
Bookmarks
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
65%
(hard)
Question Stats:
54% (01:44) correct
46%
(01:51)
wrong
based on 929
sessions
History
Date
Time
Result
Not Attempted Yet
A certain airport security scanner designed to detect explosives in luggage will alert the scanner’s operator whenever the piece of luggage passing under the scanner contains an explosive. The scanner will erroneously alert the operator for only one percent of the pieces of luggage that contain no explosives. Thus in ninety‑nine out of a hundred alerts explosives will actually be present.
The reasoning in the argument is flawed because the argument
(A) ignores the possibility of the scanner’s failing to signal an alert when the luggage does contain an explosive
(B) draws a general conclusion about reliability on the basis of a sample that is likely to be biased
(C) ignores the possibility of human error on the part of the scanner’s operator once the scanner has alerted him or her
(D) fails to acknowledge the possibility that the scanner will not be equally sensitive to all kinds of explosives
(E) substitutes one group for a different group in the statement of a percentage
The reasoning in the argument is flawed because the argument
(A) ignores the possibility of the scanner’s failing to signal an alert when the luggage does contain an explosive
(B) draws a general conclusion about reliability on the basis of a sample that is likely to be biased
(C) ignores the possibility of human error on the part of the scanner’s operator once the scanner has alerted him or her
(D) fails to acknowledge the possibility that the scanner will not be equally sensitive to all kinds of explosives
(E) substitutes one group for a different group in the statement of a percentage
10 Jul 2018, 18:59
Kudos
Bookmarks
IMO ANSWER E:
This is how: acc to the premise, the scanner will show 1% of false positive for all non-explosive luggage
Let's take nos: 100 non-explosive pieces of luggage, the scanner will result in 1 case of False positive but based
on this information, we cant deduce the accuracy for all the luggage which contain explosives as we have
info available for the accuracy of false + for non-explosive Luggage
This is how: acc to the premise, the scanner will show 1% of false positive for all non-explosive luggage
Let's take nos: 100 non-explosive pieces of luggage, the scanner will result in 1 case of False positive but based
on this information, we cant deduce the accuracy for all the luggage which contain explosives as we have
info available for the accuracy of false + for non-explosive Luggage
General Discussion
03 Jul 2018, 11:29
Kudos
Bookmarks
Answer is E? Incorrectly comparing no. Of erroneous alerts with no. Of pieces of luggage with no explosives
Sent from my iPhone using GMAT Club Forum mobile app
Sent from my iPhone using GMAT Club Forum mobile app
