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:
If t is a positive integer and r is the remainder when [#permalink]
10 Apr 2009, 06:31
00:00
A
B
C
D
E
Difficulty:
(N/A)
Question Stats:
50% (04:47) correct
50% (02:05) wrong based on 8 sessions
This topic is locked. If you want to discuss this question please re-post it in the respective forum.
If t is a positive integer and r is the remainder when \(t^2+5t+6\) is divided by 7, what is the value of r? (1) When t is divided by 7, the remainder is 6 (2) When t^2 is divided by 7, the remainder is 1
EDIT: there was a typo - now corrected.
Last edited by seofah on 10 Apr 2009, 22:46, edited 1 time in total.
I think neither of the statements alone is sufficient, because you cannot say e.g. in stmnt1 that t=7q+6 for sure. The quotient here does not have to equal the quotient from the question stem.
I hope that some one wil give some short answer. But as far as solution is concerned, here it is.. But it took me almost 5 minutes.. so .. of course.. i know.. my solution is not advisable.
From one, t-6 is divisible by 7, implies that t>= 6, but it can have values..6,13,20,27,34 etc..so 1 is not enough From 2) t^2 -1 is divisible by 7, implies that t >=6, but this equation is also satisfied by,6,8,13,27,.... So, 2 is also not enough alone.
combining 1 and 2, we have that t can have value 13,27,... in both the case, the remainder is 2, hence combing 1 and 2 we cn answer. C is the answer.
botirvoy wrote:
If t is a positive integer and r is the remainder when t^2+5t+6 is divided by 7, what is the value of r? (1) When t is divided by 7, the remainder is 6 (2) When t^2 is divided by 7, the remainder is 1
I think neither of the statements alone is sufficient, because you cannot say e.g. in stmnt1 that t=7q+6 for sure. The quotient here does not have to equal the quotient from the question stem.
I think neither of the statements alone is sufficient, because you cannot say e.g. in stmnt1 that t=7q+6 for sure. The quotient here does not have to equal the quotient from the question stem.
I think you are correct, stmnt 1 is sufficient. I got confused while picking numbers. I got that stmnt 2 is sufficient as well, though. Could you explain a deficiency:
I think you are correct, stmnt 1 is sufficient. I got confused while picking numbers. I got that stmnt 2 is sufficient as well, though. Could you explain a deficiency:
I think you are correct, stmnt 1 is sufficient. I got confused while picking numbers. I got that stmnt 2 is sufficient as well, though. Could you explain a deficiency:
now result will vary with k as this is only factor that would be driving remainder everything else in mutlitple of 7.
Here different values of k will result in different value of r, there fore, this is not suff.
Thanks.. that was good.. Although, we can .. take your last expression.. 7k +7+ 5 sqrt(7k+1) Now, the only thing that contribute the remainder is 5 sqrt(7k+1) but sqrt(7k+1 ) = t so.. it is 5t/7... and t > 0.. so it can have multiple values... It was just a perspective....Not done anything from my side.
Re: Remainder - GMATPrep2 [#permalink]
21 Oct 2009, 18:17
2
This post received KUDOS
Here's a different approach, which took me 30 seconds:
1st. t^2+5t+6 = (t+2)(t+3) (easy to spot this one)
2nd. Work the other way around: stat1 says t=7k+6 => t+2=7k+8 =8k+1, and t+3=7k+9 =8k+2 =>(8k+1)(8k+2) => r=1*2 => remainder is always 2
For statement 2, it was obvious to me that it was not sufficient, so quickly tried so numbers and got that the condition was valid for both 6^2 and 8^2. I like hemantsood's algebraic approach.
btw, this is a gprep problem. _________________
Please kudos if my post helps.
gmatclubot
Re: Remainder - GMATPrep2
[#permalink]
21 Oct 2009, 18:17