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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 350,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

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 0<x<y, is y-x < 0.00005 [#permalink]
05 Apr 2012, 15:46

11

This post received KUDOS

Expert's post

6

This post was BOOKMARKED

If 0<x<y, is y-x < 0.00005

Notice that 0.00005=\frac{5}{100,000}=\frac{3}{60,000}, and \frac{1}{15,000}=\frac{4}{60,000}.

So, we can rewrite the question as:

If 0<x<y, is y-x<3

(1) x>1 --> if x=2 and y=3 then the answer is YES but if x=2 and y=5 the answer is NO. Not sufficient. (2) y<4 --> if x=2 and y=3 then the answer is YES but if x=0.5 and y=3.5 the answer is NO. Not sufficient.

(1)+(2) Remember we can subtract inequalities if their signs are in opposite directions --> subtract (1) from (2): y-x<4-1 --> y-x<3. Sufficient.

Re: If 0<x<y, is y-x < 0.00005 [#permalink]
05 Apr 2012, 16:57

1

This post received KUDOS

imhimanshu wrote:

If 0<x<y, is y-x < 0.00005

(1) x>1/60,000 (2) y<1/15,000

1) NS - nothing about y 2) NS - nothing about x

So it's between E and C

Is y-x < 1/20,000? LT = less than GT = Great than LT 1/15,000 - GT 1/60,000 < 1/20,000. Multiply by 60,000 to simplify results in LT 4 - GT 1 < 3? Test extremes - 3.9 - 1.1 = 2.8 . YES ...sufficient. C

Re: If 0<x<y, is y-x < 0.00005 [#permalink]
21 Feb 2013, 16:53

yezz wrote:

DelSingh wrote:

If 0<x<y, is y-x < 0.00005

(1) x>1/60,000 (2) y<1/15,000

this ain't 700 or 600-700 level question , it is way sub 600

anyways

the question is asking whether the difference between both +ve numbers x,y is very small ie. 5/100,000 = 1/20,000

obviously each alone is not suff

both

subtract 2 from 1

x-y >-1/20,000... i.e. y-x<1/20,000.....an then answer is a definite yes ...c

I took off the difficulty, but GMAT Prep did rate this medium level.

Anyway, I understand why the both statements are insufficient but I do not know how you combines them? What did you when you 'subtracted 2 from 1'? _________________

If my post has contributed to your learning or teaching in any way, feel free to hit the kudos button ^_^

Re: If 0<x<y, is y-x < 0.00005 [#permalink]
21 Feb 2013, 22:26

When you subtract 1 from 2, you get the value of y-x. However, since we know only one sided limits of these values, let's consider those values.

y-x=(1/15000)-(1/60,000)

Taking L.CM. y-x=1/20,000

y-x=0.00005

However, this just gives us the limit of the difference. Since y<1/15,000 and x>1/60,000, a bigger number on the L.H.S is being subtracted from a smaller number and hence, the actual difference will be less than 1/20,000. This is by applying concept. Let us test values for better understanding.

For e.g. the value of y could be y=1/20,000(the greater the denominator, the smaller the number and hence y>1/15000) and x=1/40,000(by similar idea)

Re: If 0<x<y, is y-x < 0.00005 [#permalink]
21 Feb 2013, 22:37

8

This post received KUDOS

Expert's post

4

This post was BOOKMARKED

DelSingh wrote:

If 0<x<y, is y-x < 0.00005

(1) x>1/60,000 (2) y<1/15,000

Source: GMAT Prep question pack 1

There are two ways to deal with it.

Method 1:

Is y-x < 0.00005?

We can see that both statements alone are not sufficient.

(1) x>1/60,000 (2) y<1/15,000

We know that we can add inequalities when they have the same sign ie. a < b c < d then, a+c < b+d

Also, when we multiply an inequality by -1, the inequality sign flips. x>1/60,000 implies -x < -1/60,000

You can add these two inequalities: -x < -1/60,000 and y<1/15,000 to get y-x < 1/15000 - 1/60,000 which is y-x < 1/20,000 i.e. y-x < 0.00005

Another method is to see this on the number line. Draw a number line to understand this.

0<x<y implies that x and y are both positive and x is to the left of y on the number line. Is y-x < 0.00005 means is the distance between x and y less than .00005?

(1) x>1/60,000 means x lies to the right of 1/60,000

(2) y<1/15,000 means y lies to the left of 4/60,000

So the distance between them must be less than 4/60,000 - 1/60,000 = 3/60,000 = .00005 _________________

Re: If 0<x<y, is y-x < 0.00005 [#permalink]
21 Feb 2013, 23:20

1

This post received KUDOS

If 0<x<y, is y-x < 0.00005

(1) x>1/60,000 (2) y<1/15,000

Solution: (Answer is C)

What do we know?

X is positive and Y is greater than X. What do we need to know?

Is Y is less than 0.00005 + X?

Whenever you face a Data Sufficiency question asking Yes, No. Simply substitute and try to disprove the statement. Statement(1):

X is greater than 1/60,000 = 0.00001666

Which does not tell any relation between X and Y

Hence it is insufficient.

Statement (2) is also insufficient as it only tells that Y is less than 0.000066 (It is very important to know the importance of converting fractions to percentage)

If we combine both the statements, we get that X is greater than 0.000016 and Y is less than 0.000066

Now the question is asking us that y-x<0.00005, to try to disprove that we need to maximize y-x and for that let us get the maximum value of y and minimum value of x. Let us say y = 0.000065 and x = 0.000017 So the maximum difference is = 0.000065 - 0.000017 = 0.000048

Hence combining both the statements we can say that y-x will always be less than 0.000048. Hence answer is (C) _________________

Re: If 0<x<y, is y-x < 0.00005 [#permalink]
22 Feb 2013, 03:29

1

This post received KUDOS

DelSingh wrote:

yezz wrote:

DelSingh wrote:

If 0<x<y, is y-x < 0.00005

(1) x>1/60,000 (2) y<1/15,000

this ain't 700 or 600-700 level question , it is way sub 600

anyways

the question is asking whether the difference between both +ve numbers x,y is very small ie. 5/100,000 = 1/20,000

obviously each alone is not suff

both

subtract 2 from 1

x-y >-1/20,000... i.e. y-x<1/20,000.....an then answer is a definite yes ...c

I took off the difficulty, but GMAT Prep did rate this medium level.

Anyway, I understand why the both statements are insufficient but I do not know how you combines them? What did you when you 'subtracted 2 from 1'?

for 2 ineq to subtract they have to be with opposit direction , one of them is bigger than and 2nd is smaller than and what u do is keep the sign ( direction in terms of bigger than or smaller than) of the ineq from which u subtract the 2nd ....

Another way of seeing it is as follows

if we subtract 1 from 2

is like flipping the sign of 1 and adding it to the 2nd , thus

x>1/60,000 becomes -x<-1/60,000...............1 after changing direction ( flipping the sign)

Re: If 0<x<y, is y-x < 0.00005 [#permalink]
02 Mar 2013, 10:07

I want to follow this posting. _________________

if anyone in this forum is living in Bradford, Leeds or nearby areas, pls, email to me, thanghnvn@gmail.com. I have a small thing to ask you. Thank you

Re: If 0 < x < y , is y - x < 0.00005 ? [#permalink]
27 Apr 2013, 01:58

(1) Insufficient. We know nothing about y. (2) Insufficient. We know nothing about x.

(1)+(2) Sufficient. We know that y<\frac{1}{15,000} and -x<-\frac{1}{60,000}. If we add this two inequalities we will get: y-x<\frac{1}{15,000}-\frac{1}{60,000}=\frac{1}{20,000}=0.00005

The correct answer is C. _________________

I'm happy, if I make math for you slightly clearer And yes, I like kudos:)

Re: If 0<x<y, is y-x < 0.00005 [#permalink]
05 Jun 2014, 02:01

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

Re: If 0<x<y, is y-x < 0.00005 [#permalink]
05 Dec 2014, 16:45

Bunuel wrote:

If 0<x<y, is y-x < 0.00005

Notice that 0.00005=\frac{5}{100,000}=\frac{3}{60,000}, and \frac{1}{15,000}=\frac{4}{60,000}.

So, we can rewrite the question as:

If 0<x<y, is y-x<3

(1) x>1 --> if x=2 and y=3 then the answer is YES but if x=2 and y=5 the answer is NO. Not sufficient. (2) y<4 --> if x=2 and y=3 then the answer is YES but if x=0.5 and y=3.5 the answer is NO. Not sufficient.

(1)+(2) Remember we can subtract inequalities if their signs are in opposite directions --> subtract (1) from (2): y-x<4-1 --> y-x<3. Sufficient.

Answer: C.

Hi Bunuel,

This is great. I actually went the long division route and it took quite some time.

Can you suggest similar problems where we manipulate fractions/decimals as such?

I clicked on the tab on the top right but it just let me to regular inequalities problems.

Thanks,

gmatclubot

Re: If 0<x<y, is y-x < 0.00005
[#permalink]
05 Dec 2014, 16:45

Wow...I'm still reeling from my HBS admit . Thank you once again to everyone who has helped me through this process. Every year, USNews releases their rankings of...

Almost half of MBA is finally coming to an end. I still have the intensive Capstone remaining which started this week, but things have been ok so far...