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.
It appears that you are browsing the GMAT Club forum unregistered!
Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club
Registration gives you:
Tests
Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.
Applicant Stats
View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more
Books/Downloads
Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!
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:
The numbers of books read by 7 students last year were 10, 5 [#permalink]
11 Jun 2010, 06:44
1
This post received KUDOS
2
This post was BOOKMARKED
00:00
A
B
C
D
E
Difficulty:
45% (medium)
Question Stats:
60% (01:54) correct
40% (00:55) wrong based on 190 sessions
The numbers of books read by 7 students last year were 10, 5, p , q , r , 29 and 20. What was the range of the numbers of books read by the 7 students last year?
How I went ahead 1) Insuff because no info on r 2) Insuff because no info on q
1) & 2) p>5 and p<q and p<r<15 => p=b/w 6 and 13 max value of p =13,min value of p possible = 6 max value of r=14,min value of r=7 Range = Largest-Smallest So 29-5=24.So answer is (C) .Why is this wrong.Please help
Re: Need help on Range problem in Data Sufficiency [#permalink]
11 Jun 2010, 06:55
What about q? There is only one statement that talks about q which says q>p. That doesn't tell us anything about the maximum possible value of q. What if q>29?
Re: Need help on Range problem in Data Sufficiency [#permalink]
28 Aug 2013, 06:53
sjayasa wrote:
What about q? There is only one statement that talks about q which says q>p. That doesn't tell us anything about the maximum possible value of q. What if q>29?
Re: The numbers of books read by 7 students last year were 10, 5 [#permalink]
05 Sep 2013, 07:08
By combining both statements , we may get range of P & R. But we are not getting any maximum possible value of Q. SO E is the correct option _________________
Practice Makes a Man Perfect. Practice. Practice. Practice......Perfectly
Helpful Geometry formula sheet:best-geometry-93676.html I hope these will help to understand the basic concepts & strategies. Please Click ON KUDOS Button.
Re: The numbers of books read by 7 students last year were 10, 5 [#permalink]
03 Jan 2015, 09:58
Hello from the GMAT Club BumpBot!
Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________
Re: The numbers of books read by 7 students last year were 10, 5 [#permalink]
03 Jan 2015, 12:20
Expert's post
Hi All,
Note-taking is a MUST on Test Day. Here, with so many numbers and variables to keep track of, missing one small detail could very easily cost you the question (and not taking enough notes is a silly reason to get a question wrong)..
Here, we're given 7 values for the number of books read by 7 students: 5, 10, 20, 29, P, Q and R.
**NOTE: I have arranged the numbers from least to greatest; the variables could be ANY number greater than or equal to 0)**
We're asked for the RANGE of values, which means that we'll need to know the LARGEST - SMALLEST numbers in this set of 7 values.
Fact 1: 5 < P < Q
Since we don't know anything about the values of P, Q and R, it would be easy to say this Fact is insufficient, but here's the PROOF:
IF.... P = 6 Q = 7 R = 8 Range = 29 - 5 = 24
P = 6 Q = 7 R = 100 Range = 100 - 5 = 95 Fact 1 is INSUFFICIENT
Fact 2: P < R < 15
Much like in Fact 1, we don't know the value of P, Q and R. Here's the PROOF that this is insufficient.
IF.... P = 6 R = 7 Q = 8 Range = 29 - 5 = 24
P = 6 R = 7 Q = 50 Range = 50 - 5 = 45 Fact 2 is INSUFFICIENT
Combined, we know...
5 < P < Q P < R < 15
We can use the SAME TESTs that we used in Fact 2 (above) to prove that the answer is inconsistent. Combined, INSUFFICIENT
Re: The numbers of books read by 7 students last year were 10, 5 [#permalink]
13 Jan 2016, 04:23
Hello from the GMAT Club BumpBot!
Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________
Re: The numbers of books read by 7 students last year were 10, 5 [#permalink]
13 Jan 2016, 22:09
1
This post received KUDOS
Expert's post
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.
The numbers of books read by 7 students last year were 10, 5, p , q , r , 29 and 20. What was the range of the numbers of books read by the 7 students last year?
(1) 5 < p < q (2) p < r < 15
In the original condition, there are 3 variables(p,q,r), which should match with the number of equations. So you need 3 equations. For 1) 1 equation, for 2) 1 equation, which is likely to make E the answer. When 1) & 2), it becomes 5<p<r<15. However, you don’t know q’s value, which is not sufficient. Therefore, the answer is E.
For cases where we need 3 more equations, such as original conditions with “3 variables”, or “4 variables and 1 equation”, or “5 variables and 2 equations”, we have 1 equation each in both 1) and 2). Therefore, there is 80% chance that E is the answer (especially about 90% of 2 by 2 questions where there are more than 3 variables), while C has 15% chance. These two are the majority. In case of common mistake type 3,4, the answer may be from A, B or D but there is only 5% chance. Since E is most likely to be the answer using 1) and 2) separately according to DS definition (It saves us time). Obviously there may be cases where the answer is A, B, C or D. _________________
As I’m halfway through my second year now, graduation is now rapidly approaching. I’ve neglected this blog in the last year, mainly because I felt I didn’...
Hilary Term has only started and we can feel the heat already. The two weeks have been packed with activities and submissions, giving a peek into what will follow...
Ninety-five percent of the Full-Time Class of 2015 received an offer by three months post-graduation, as reported today by Kellogg’s Career Management Center(CMC). Kellogg also saw an increase...