It is currently 19 Mar 2018, 11:43

GMAT Club Daily Prep

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

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Which of the following can be a remainder of X/Y if both X

Author Message
Manager
Joined: 01 Apr 2006
Posts: 177
Which of the following can be a remainder of X/Y if both X [#permalink]

Show Tags

11 Sep 2008, 04:09
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 10 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Which of the following can be a remainder of X/Y if both X and Y are positive integers and X/Y =2.625?

a) 2
b) 4
c) 5
d) 8
e) 9
Current Student
Joined: 11 May 2008
Posts: 552

Show Tags

11 Sep 2008, 04:49
2.625=2+625/1000 = 21/8 .

21/8 leaves a remainder of 5.
ans = C
Intern
Joined: 16 Feb 2006
Posts: 30
Location: ZURICH

Show Tags

11 Sep 2008, 05:14
X/Y = 2.625
or, X = 2.625 x Y
or, X = 2Y + 0.625Y
or, X = 2Y + 625/1000 x Y
or X = 2Y + 5/8Y

remainder will be 5 .
_________________

TRY N TRY UNTIL U SUCCEED

Manager
Joined: 01 Apr 2006
Posts: 177

Show Tags

11 Sep 2008, 06:47
OA is C

Thanks guys... all clear answers. I unfortunately make a silly mistake on this one... did 6/8 instead... grr.
VP
Joined: 30 Jun 2008
Posts: 1019

Show Tags

11 Sep 2008, 07:50
Quoting Ian Stewart's explanation on a similar problem :
IanStewart wrote:
Quote:
If s and t are positive integers such that s/t = 64.12, which of the following could be the remainder when s is divided by t?

(a) 2
(b) 4
(c) 8
(d) 20
(e) 45

When we divide s by t we can always write:

s/t = q + r/t

where q is the 'quotient', and r is the 'remainder', where 0 <= r < t (so 0 <= r/t < 1). That's essentially the definition of the remainder, so is quite important to understand- many remainder questions will be difficult to answer otherwise. If

s/t = 64.12 = 64 + 12/100

then 64 is the quotient, while the fractional part, 12/100, is equal to r/t (compare with the other equation above). This doesn't mean 12 is the remainder, however- that would only be true if t was equal to 100. Still, we can find what values r might take. Rewriting:

r/t = 12/100
r/t = 3/25
25r = 3t

and if r and t are integers, the primes that divide the right side of this equation must also divide the left- in particular r must be divisible by 3. Only one answer choice is divisible by 3- E, or 45- so it's the only possible value of r among the answer choices.

There are many other possible values for r- any multiple of 3 would have been a possible answer, in fact.

Here in our question we have

x/y = 2.625 = 2 + (625/1000) = 2 + (5/8)

if r is remainder then , r/y = 5/8
8r = 5y (and we know from the question that r and y are integers)

Only one choice is a multiple of 5 here. So the answer is C

Thanks Ian
_________________

"You have to find it. No one else can find it for you." - Bjorn Borg

Re: remainder PS   [#permalink] 11 Sep 2008, 07:50
Display posts from previous: Sort by