GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 23 Mar 2019, 05:50 ### 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

#### Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here. ### Request Expert Reply # If x and y are positive integers, which of the following could be

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

General GMAT Forum Moderator V
Joined: 29 Jan 2015
Posts: 1173
Location: India
WE: General Management (Non-Profit and Government)
If x and y are positive integers, which of the following could be  [#permalink]

### Show Tags

1 00:00

Difficulty:   25% (medium)

Question Stats: 79% (01:17) correct 21% (01:21) wrong based on 19 sessions

### HideShow timer Statistics

If x and y are positive integers, which of the following could be the value of 1/x - 1/y?

I. 1

II. 3/4

III. 5/36

(A) I only

(B) II only

(C) III only

(D) I and II only

(E) II and III only

_________________

If you liked my post, kindly give me a Kudos. Thanks.

Math Expert V
Joined: 02 Sep 2009
Posts: 53795
Re: If x and y are positive integers, which of the following could be  [#permalink]

### Show Tags

rohan2345 wrote:
104. If x and y are positive integers, which of the following could be the value of 1/x - 1/y?

I. 1

II. 3/4

III. 5/36

________________________
_________________
VP  P
Joined: 31 Oct 2013
Posts: 1273
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
Re: If x and y are positive integers, which of the following could be  [#permalink]

### Show Tags

rohan2345 wrote:
If x and y are positive integers, which of the following could be the value of 1/x - 1/y?

I. 1

II. 3/4

III. 5/36

(A) I only

(B) II only

(C) III only

(D) I and II only

(E) II and III only

1/x - 1/y

y - x / xy.

Scan the answer choices.

I) 1

y -x / xy = 1

y -x = xy.

It is NOT possible as both x and y are positive integers.

II) y -x / xy = 3/4

4*1 = 4

4 - 1 / 4*1 = 3/4.

This option is possible.

III) y -x / xy = 5/36.

4*9 = 36.

9 - 4 / 4*9 = 5/36.

So, This option is correct.

E is the correct answer.
Senior Manager  P
Joined: 28 Jul 2016
Posts: 259
Location: India
Concentration: Finance, Human Resources
GPA: 3.97
If x and y are positive integers, which of the following could be  [#permalink]

### Show Tags

$$\frac{1}{x} - \frac{1}{y} = \frac{y-x}{xy}$$
now given x and y are positive numbers.
hence 1/(some positive number ) is always less than equal 1 and we are subtracting two such numbers.
hence difference will be even less than 1.
Hence option 1 out .
II and III can be the options.
which can be proven by
for II x =1 and y = 4=$$\frac{y-x}{xy}$$= 3/4
for III x=4 and y =9 = $$\frac{9-4}{36} = \frac{5}{36}$$
Thus answer E. since II and III are possible
_________________

Please give Kudos. Kudos encourage active discussions and help the community grow If x and y are positive integers, which of the following could be   [#permalink] 06 Mar 2019, 21:07
Display posts from previous: Sort by

# If x and y are positive integers, which of the following could be

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.  