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: Number propierties [#permalink]
19 Sep 2011, 02:27

GMATPASSION wrote:

Gud Explanation Fluke. Hope my explanations above were also correct although a little traditional

Oh, absolutely!! In fact, Kudos for that.

I believe you used the concept of mathematical induction, in which all terms but one are divisible by the denominator. I remember Karishma's describing it once. I don't remember that exactly. _________________

Re: Number propierties [#permalink]
19 Sep 2011, 02:30

fluke wrote:

GMATPASSION wrote:

Gud Explanation Fluke. Hope my explanations above were also correct although a little traditional

Oh, absolutely!! In fact, Kudos for that.

I believe you used the concept of mathematical induction, in which all terms but one are divisible by the denominator. I remember Karishma's describing it once. I don't remember that exactly.

Thanks for my first kudos buddy. 'Mathematical Induction' Wats dat? Never Heard of that??

Re: Number propierties [#permalink]
19 Sep 2011, 21:22

2

This post received KUDOS

Expert's post

GMATPASSION wrote:

Thanks for my first kudos buddy. 'Mathematical Induction' Wats dat? Never Heard of that??

Responding to a PM:

Actually it was a discussion on 'Binomial Theorem' (Induction is an altogether different concept which is out of GMAT scope) Binomial theorem comes in handy in many remainder questions.

With a power of 3, it is easy to expand the expression and see that only 1 will be the remainder (as GMATPASSION did). For higher powers, binomial theorem can be used. I have put up a post on the Veritas blog discussing it and its applications. Here is the link. Get back in case there are any doubts.

Re: Number propierties [#permalink]
19 Sep 2011, 23:24

VeritasPrepKarishma wrote:

GMATPASSION wrote:

Thanks for my first kudos buddy. 'Mathematical Induction' Wats dat? Never Heard of that??

Responding to a PM:

Actually it was a discussion on 'Binomial Theorem' (Induction is an altogether different concept which is out of GMAT scope) Binomial theorem comes in handy in many remainder questions.

With a power of 3, it is easy to expand the expression and see that only 1 will be the remainder (as GMATPASSION did). For higher powers, binomial theorem can be used. I have put up a post on the Veritas blog discussing it and its applications. Here is the link. Get back in case there are any doubts.

Re: What is the remainder when the positive integer n is divided [#permalink]
04 Jul 2013, 02:12

1

This post received KUDOS

Expert's post

What is the remainder when the positive integer n is divided by the positive integer k, where k>1

(1) n=(k+1)^3= k^3 + 3k^2 + 3k + 1=k(k^2+3k+3)+1 --> first term, k(k^2+3k+3), is obviously divisible by k and 1 divide by k yields the remainder of 1 (as k>1). Sufficient.

(2) k=5. Know nothing about n, hence insufficient.

Re: What is the remainder when the positive integer n is divided [#permalink]
04 Jul 2013, 19:07

1

This post received KUDOS

Expert's post

fozzzy wrote:

The expansion of (K+1)^3 needs to be memorized? BTW great explanation @fluke

In case you do forget the expansion/don't know it, just multiply:

(K+1)^3 = (K+1)(K^2 + 2K + 1) (We certainly know the expansion of (K+1)^2 or we can find it my multiplying (K+1)(K+1)) (K+1)^3 = K^3 + 3K^2 + 3K + 1 _________________