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
we will pick new questions that match your level based on your Timer History
Track Your Progress
every week, we’ll send you an estimated GMAT score based on your performance
Practice Pays
we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
Join Our "Master Multi-Source Reasoning Questions by Owning the Dataset” Session! Tackling Multi-Source Reasoning (MSR) on the GMAT can be like navigating through a complex maze.
Earning a 100th percentile score on the GMAT Focus is no easy feat. But with Target Test Prep, any score is possible. Take Ming, a TTP student who recently scored 755 (Q86/V88/DI86) on the GMAT Focus Edition.
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
When a player in a certain game removed a marble from a bag a certain
[#permalink]
10 Aug 2017, 11:28
Show timer
00:00
A
B
C
D
E
Difficulty:
55%
(hard)
Question Stats:
53%
(02:15)
correct
47%
(01:10)
wrong
based on 15
sessions
HideShow
timer Statistics
When a player in a certain game removed a marble from a bag a certain number of times, 3 more blue marbles than red marbles resulted. The bag consisted of only blue and red marbles. How many times did a blue marble result?
(1) A red marble resulted 3/7 of the time.
(2) The player received 2 points each time a blue marble resulted and lost 2 points each time a red marble resulted, for a total of 6 points.
This Question is Locked Due to Poor Quality
Hi there,
The question you've reached has been archived due to not meeting our community quality standards. No more replies are possible here.
Looking for better-quality questions? Check out the 'Similar Questions' block below
for a list of similar but high-quality questions.
Want to join other relevant Problem Solving discussions? Visit our Data Sufficiency (DS) Forum
for the most recent and top-quality discussions.
Re: When a player in a certain game removed a marble from a bag a certain
[#permalink]
11 Aug 2017, 17:25
1
Kudos
Expert Reply
artisood17 wrote:
When a player in a certain game removed a marble from a bag a certain number of times, 3 more blue marbles than red marbles resulted. The bag consisted of only blue and red marbles. How many times did a blue marble result?
(1) A red marble resulted 3/7 of the time.
(2) The player received 2 points each time a blue marble resulted and lost 2 points each time a red marble resulted, for a total of 6 points.
I don't have the highest opinion of this question. The phrasing of the stem is awkward: it makes me suspect that this question was written by a non-native speaker whose understanding of math far exceeds his understanding of English. All the Quant questions on the GMAT are impeccable in their language: the words and numbers are handled with the same level of precision.
It's not clear to me that the picking marbles set-up is the clearest set-up for what the question writer was trying to test.
Here's the solution.
Let R = # of red marbles picked, and B = # of blue marbles picked
He picks a total of N marbles. We want to know N. We know N = R + B, and B = R + 3. We have three variables.
Statement #1: A red marble resulted 3/7 of the time. This means that R = (3/7)N The direct implication is that if 3/7 were red, the other 4/7 had to be blue. B = (4/7)N We know B - R = 3 (4/7)N - (3/7)N = 3 (1/7)N = 3 N = 21 He picked a total of 21 marbles, 12 blues and 9 red.
With this statement, we were able to compute everything. This statement, alone and by itself, is sufficient.
Statement #2: The player received 2 points each time a blue marble resulted and lost 2 points each time a red marble resulted, for a total of 6 points. This statement is way way too long to be one of the statements of a GMAT DS question. Much of this information easily could have be included in the prompt description. The question writer here is woefully uninformed about the standards of the GMAT.
Nevertheless, this is a mathematically interesting statement because it's a tautological statement.
If he gains two points for every blue and loses two for every red, then every red + blue pair would be worth zero. We know from the prompt that we could pair up all the marbles into red + blue pairs, and we would be left with just 3 unpaired blues, which would be worth 6 points. From the prompt information, we already know this numerical result: this new statement adds no new mathematical information--that's precisely the definition of a tautological statement.
This statement is completely insufficient. In essence, it contains no information different from that in the prompt.
OA = (A)
A mathematically interesting yet ultimately flawed question. One really has to understand many things to write a solid GMAT Quant practice question, although these are considerably easier to produce than are solid GMAT Verbal practice questions.