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:

Re: If r is the remainder when integer n is divided by 7, what is the valu [#permalink]

Show Tags

27 Oct 2014, 09:36

3

This post was BOOKMARKED

Bunuel wrote:

Tough and Tricky questions: Remainders.

If r is the remainder when integer n is divided by 7, what is the value of r?

(1) When n is divided by 21, the remainder is an odd number (2) When n is divided by 28, the remainder is 3

solution: From #1, if n = 5, remainder is 5 and is odd. if n = 7, remainder is 7 and is odd. However, remainder when n(5 or 7) is divided by 7 is different. Hence not sufficient From #2, n=3, or 31, or 59 etc, remainder is 3, Even when the above numbers are divided by 7, the remainder is still 3

Re: If r is the remainder when integer n is divided by 7, what is the valu [#permalink]

Show Tags

04 Sep 2015, 07:10

we are given n/7 = k + r (where "k" in an integer)

Stmt 1: n/21 = m + o (where "m" is an integer and "o" is odd remainder) => n = 21m +21o => n/7 = 3m + 3o (this does not gives a clear value for the remainder when n is divided by 7)

Stmt 2: n/28 = t + 3 (where "t" is an integer) => n = 28t + 28*3 => n/7 = 4t + 4*3 = 4t + 12 = (4t + 7) + 5 => the remainder when n id divided by 7 is 5 or r = 5

Since Stmt 2 is sufficient to get the answer, hence the answer would be B.

Re: If r is the remainder when integer n is divided by 7, what is the valu [#permalink]

Show Tags

07 Aug 2016, 07:24

hunterdonald wrote:

Bunuel wrote:

Tough and Tricky questions: Remainders.

If r is the remainder when integer n is divided by 7, what is the value of r?

(1) When n is divided by 21, the remainder is an odd number (2) When n is divided by 28, the remainder is 3

solution: From #1, if n = 5, remainder is 5 and is odd. if n = 7, remainder is 7 and is odd. However, remainder when n(5 or 7) is divided by 7 is different. Hence not sufficient From #2, n=3, or 31, or 59 etc, remainder is 3, Even when the above numbers are divided by 7, the remainder is still 3

Re: If r is the remainder when integer n is divided by 7, what is the valu [#permalink]

Show Tags

07 Aug 2016, 07:29

1

This post received KUDOS

Amit0507 wrote:

hunterdonald wrote:

Bunuel wrote:

Tough and Tricky questions: Remainders.

If r is the remainder when integer n is divided by 7, what is the value of r?

(1) When n is divided by 21, the remainder is an odd number (2) When n is divided by 28, the remainder is 3

solution: From #1, if n = 5, remainder is 5 and is odd. if n = 7, remainder is 7 and is odd. However, remainder when n(5 or 7) is divided by 7 is different. Hence not sufficient From #2, n=3, or 31, or 59 etc, remainder is 3, Even when the above numbers are divided by 7, the remainder is still 3

Answer should be B

Can't n b 12 in the second case?

In the 2nd case, we have the equation of the form n=28k+3.

Put the value of k=0,1,2,3,etc.. you will get n =3,31,59,..etc.

If r is the remainder when integer n is divided by 7, what is the value of r?

(1) When n is divided by 21, the remainder is an odd number (2) When n is divided by 28, the remainder is 3

We can use a variety of divisibility rules to solve this, or we can list possible values of n based on the statements. The rule for listing possible values of n is as follows: If, when N is divided by D, the remainder is R, then the possible values of N include: R, R+D, R+2D, R+3D,. . .

Target question:What is the value of r?

Statement 1: When n is divided by 21, the remainder is an odd number. There are several possible values of n that satisfy this condition. Here are two: Case a: n = 1 (since 1 divided by 21 leaves remainder 1, which is odd). Here, r = 1 Case b: n = 3 (since 3 divided by 21 leaves remainder 3, which is odd). Here, r = 3 Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: When n is divided by 28, the remainder is 3 Possible values of n: 3, 31, 59, 87, . . . We can see that for all possible values of n, the remainder is always 3 when n is divided by 7 Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: B

RELATED VIDEO FROM OUR COURSE

_________________

Brent Hanneson – Founder of gmatprepnow.com

gmatclubot

Re: If r is the remainder when integer n is divided by 7, what is the valu
[#permalink]
20 Apr 2018, 07:36