Remainder Question

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Thu Feb 06, 2014 10:43 am

Remainder Question

by sanchu » Mon Feb 10, 2014 3:58 pm
When positive integer x is divided by positive integer y, the remainder is 9. If x/y=96.12, what is the value of y?
a) 96
b)75
c) 48
d)25
e) 12

I'm having a tough time visualizing this one.

User avatar
GMAT Instructor
Posts: 1248
Joined: Thu Mar 29, 2012 2:57 pm
Location: Everywhere
Thanked: 503 times
Followed by:192 members
GMAT Score:780

by Bill@VeritasPrep » Mon Feb 10, 2014 4:11 pm
sanchu wrote:When positive integer x is divided by positive integer y, the remainder is 9. If x/y=96.12, what is the value of y?
a) 96
b)75
c) 48
d)25
e) 12

I'm having a tough time visualizing this one.
I used to forgot the relationship between the remainder and decimal forms fairly regularly, but you can always derive it using simple values.

7/4 = 1 R 3

7/4 = 1.75

Using pieces from the remainder form, how do I get the decimal .75? It must be the remainder of 3 divided by the divisor of 4.

decimal = remainder / divisor

.12 = 9/y

12/100 = 9/y

3/25 = 9/y

3y = 9*25

y=3*25

y=75
Join Veritas Prep's 2010 Instructor of the Year, Matt Douglas for GMATT Mondays

Visit the Veritas Prep Blog

Try the FREE Veritas Prep Practice Test

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2095
Joined: Tue Dec 04, 2012 3:22 pm
Thanked: 1443 times
Followed by:247 members

by ceilidh.erickson » Tue Feb 11, 2014 2:16 pm
Another way you could solve this is as a system of equations.

If, when we divide x by y, we get a remainder of 9, we could say that y times something plus 9 equals x:
ny + 9 = x

Then we're told that x/y = 96.12, which means that n must equal 96:
96y + 9 = x

We can also rearrange our given equation to say 96.12y = x.

Since both equations are equal to x, we can say:

96y + 9 = 96.12y
9 = 0.12y
y = 75
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2095
Joined: Tue Dec 04, 2012 3:22 pm
Thanked: 1443 times
Followed by:247 members

by ceilidh.erickson » Tue Feb 11, 2014 2:17 pm
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education

User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Tue Feb 11, 2014 2:38 pm
sanchu wrote:When positive integer x is divided by positive integer y, the remainder is 9. If x/y=96.12, what is the value of y?
a) 96
b)75
c) 48
d)25
e) 12
I would probably use Bill's approach, as I did here:
https://www.beatthegmat.com/dealing-with ... 69971.html

Another approach:

96.12 = 9612/100 = 4806/50 = 2403/25.

Since x/y = 2403/25 -- and x and y are integers -- y must be a multiple of 25.
Eliminate A, C and E.
If y=25 -- as stated in answer choice D -- then x=2403, in which case the remainder for x/y will be 3.
Eliminate D.

The correct answer is B.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3