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 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.
27 Apr 2020, 13:12
Kudos
Bookmarks
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
5%
(low)
Question Stats:
94% (01:25) correct
6%
(01:43)
wrong
based on 814
sessions
History
Date
Time
Result
Not Attempted Yet
In a certain history class of 17 juniors and seniors, each junior has written 2 book reports and each senior has written 3 book reports. If the 17 students have written a total of 44 book reports, how many juniors are in the class?
A. 7
B. 8
C. 9
D. 10
E. 11
PS57330.02
A. 7
B. 8
C. 9
D. 10
E. 11
PS57330.02
Updated on: 07 Apr 2022, 13:37
Originally posted by BrentGMATPrepNow on 27 Apr 2020, 21:02.
Last edited by BrentGMATPrepNow on 07 Apr 2022, 13:37, edited 1 time in total.
Last edited by BrentGMATPrepNow on 07 Apr 2022, 13:37, edited 1 time in total.
Kudos
Bookmarks
gmatt1476
STRATEGY: Upon reading any GMAT Problem Solving question, we should always ask, Can I use the answer choices to my advantage?
In this case, we can easily test the answer choices.
Now let's give ourselves up to 20 seconds to identify a faster approach.
In this case, we can also apply algebra to solve the question.
I think testing the answer choices will be faster, so I'll go with that....
APPROACH #1: Test the answer choices
Let's start by testing the middle value, since that may allow us to eliminate other answer choices as well.
C. 9 . This means 9 of the 17 students are juniors, which means the remaining 8 students must be seniors.
So, in this case, the total number of book reports = (9)(2) + (8)(3) = 18 + 24 = 42
Since we want a total of 44 book reports, answer choice C is incorrect.
Also, since each senior student writes 1 book report more than each junior student, we must increase the number of senior students in order to reach a total of 44 book reports.
So, if we want increase the number of senior students, we must decrease the number of junior students
In other words, we need fewer than 9 junior students, which means we can also eliminate answer choices D and E.
Let's test answer choice B next.
B. 8 . This means 8 of the 17 students are juniors, which means the remaining 9 students must be seniors.
So, in this case, the total number of book reports = (8)(2) + (9)(3) = 16 + 27 = 43
Since we want a total of 44 book reports, answer choice B is incorrect.
At this point, we can be certain that the correct answer must be A.
Answer: A
APPROACH #2: Algebraic approach
In a certain history class of 17 juniors and seniors...
Since the question asks us to find the number of juniors, let's let x = the number of juniors in the class
Since there are only juniors and seniors, and since there are 17 students in total, we know that 17 - x = the number of seniors in the class
Each junior has written 2 book reports and each senior has written 3 book reports. The 17 students have written a total of 44 book reports
Total number of books written by juniors = 2x
Total number of books written by seniors = 3(17 - x)
So we can write: 2x + 3(17 - x) = 44
Expand: 2x + 51 - 3x = 44
Simplify: -x + 51 = 44
Solve: x = 7
Answer: A
Cheers,
Brent
General Discussion
27 Apr 2020, 13:19
Kudos
Bookmarks
If there were 17 seniors in the class, the number of reports written would be 17*3=51
Actual number of written reports = 44
Number of juniors = (51-44) = 7
Actual number of written reports = 44
Number of juniors = (51-44) = 7
Bunuel
