About remainder, Help

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About remainder, Help

by neilcao » Tue Feb 22, 2011 7:10 am
10/2^n find the remainder?
1. n is even number
2. n is multiples of 4

how do we deal with this kind of remainder questions, when something is like 10/2^n or maybe 12/4^n....

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by Night reader » Tue Feb 22, 2011 7:35 am
st(1) turns out to make two remainders when n=1 and n=2, the remainder is 2 And when n>3 the remainder is 10 Not Sufficient;
st(2) n is multiples of 4 means n>=4 and n is divided by 4 which makes viable only one possibility for remainder = 10 Sufficient

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neilcao wrote:10/2^n find the remainder?
1. n is even number
2. n is multiples of 4

how do we deal with this kind of remainder questions, when something is like 10/2^n or maybe 12/4^n....
just follow the decision stem above :)
My knowledge frontiers came to evolve the GMATPill's methods - the credited study means to boost the Verbal competence. I really like their videos, especially for RC, CR and SC. You do check their study methods at https://www.gmatpill.com

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by Ashish8 » Tue Feb 22, 2011 10:39 am
I got the same thing. When N is a multiple of 4, then 2^N will always be greater than 10. This division will always yield the dividend as the remainder. Hence, 10.

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by clock60 » Tue Feb 22, 2011 10:41 am
here i got E
(1) n-even integer
if n=0, 10=2^0*10+0 remaider 0 ( 0 is even)
if n=2, 10=(2^2)*2+2 remaider 2
if n=4, 10=2^4*0+10 remaider 10
not suff
(2) n is multiple of 4
if n=0 remaider 0 (0 is a multiple of 4)
if n=4 then 10=2^4*0+10 remaider 10
not suff
together we have two versions 0 and 10 so both insuff

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by Ashish8 » Tue Feb 22, 2011 10:52 am
ahh, you're right, 0 is a multiple of all numbers.

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by Night reader » Tue Feb 22, 2011 11:13 am
@clock, technically you are absolutely right!!! ... and welcome to the GMAT math conventions. Please read below a fragment from the BTG thread, the content copied/pasted belongs to Ron Purewal and hear how an informed test taker could reason one's solution (though, it doesn't help to excel in exam :( )

"... under the traditional mathematical definition, yes, 0 and negative multiples are counted as 'multiples'.

HOWEVER,

to date, as far as i know, there has never been an official problem requiring the use of 0 or negative numbers as 'multiples' of positive integers. in fact, every single problem dealing with factors, multiples, primes, divisibility, and the like has been restricted, by fiat, to positive integers.
"

Source https://www.beatthegmat.com/negative-mul ... 12560.html

Therefore, my friend I chose B-opsss, you could also mention -ve multiples in your analysis of st(2)
clock60 wrote:here i got E
(1) n-even integer
if n=0, 10=2^0*10+0 remaider 0 ( 0 is even)
if n=2, 10=(2^2)*2+2 remaider 2
if n=4, 10=2^4*0+10 remaider 10
not suff
(2) n is multiple of 4
if n=0 remaider 0 (0 is a multiple of 4)
if n=4 then 10=2^4*0+10 remaider 10
not suff
together we have two versions 0 and 10 so both insuff
My knowledge frontiers came to evolve the GMATPill's methods - the credited study means to boost the Verbal competence. I really like their videos, especially for RC, CR and SC. You do check their study methods at https://www.gmatpill.com

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by clock60 » Tue Feb 22, 2011 11:24 am
above post looks very impressive
may be i am wrong
waiting for the oa
( but honestly i don`t like this problem at all, to me it is poorly constructed-my own opinion)