It is currently 25 May 2019, 23:48

### 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

# Which of the following is an equation of a line that doe NO

Author Message
TAGS:
Founder
Joined: 18 Apr 2015
Posts: 6631
Followers: 107

Kudos [?]: 1274 [0], given: 6002

Which of the following is an equation of a line that doe NO [#permalink]  05 Dec 2017, 14:47
Expert's post
00:00

Question Stats:

46% (00:24) correct 53% (00:47) wrong based on 26 sessions
Which of the following is an equation of a line that doe NOT contain any points in the xy-plane for which both coordinates are integers?

A.$$y=4$$

B. $$y=\frac{1}{2x}$$

C.$$y=x+3$$

D. $$y= x+\frac{1}{2}$$

E. $$y=\frac{1}{2x} + 3$$
[Reveal] Spoiler: OA

_________________

Last edited by chetan2u on 03 Dec 2018, 18:57, edited 1 time in total.
Corrected the OA
Director
Joined: 20 Apr 2016
Posts: 864
WE: Engineering (Energy and Utilities)
Followers: 11

Kudos [?]: 645 [1] , given: 142

Re: Which of the following is an equation of a line that doe NO [#permalink]  06 Dec 2017, 07:57
1
KUDOS
Carcass wrote:
Which of the following is an equation of a line that doe NOT contain any points in the xy-plane for which both coordinates are integers?

A.$$y=4$$

B. $$y=\frac{1}{2x}$$

C.$$y=x+3$$

D. $$y= x+\frac{1}{2}$$

E. $$y=\frac{1}{2x} + 3$$

[Reveal] Spoiler: OA
OA in 24h

Here looking at the values,

Only option D , which is $$y= x+\frac{1}{2}$$ is not possible because for any integer value of x, y will be fraction
_________________

If you found this post useful, please let me know by pressing the Kudos Button

Rules for Posting https://greprepclub.com/forum/rules-for ... -1083.html

Intern
Joined: 27 Oct 2018
Posts: 49
Followers: 0

Kudos [?]: 13 [1] , given: 27

Re: Which of the following is an equation of a line that doe NO [#permalink]  02 Nov 2018, 11:32
1
KUDOS
How is option E not right?
Intern
Joined: 15 Sep 2018
Posts: 23
Followers: 0

Kudos [?]: 6 [0], given: 2

Re: Which of the following is an equation of a line that doe NO [#permalink]  03 Dec 2018, 13:14
indiragre18 wrote:
How is option E not right?

I would also like to know because I did this with 0 and I remembered you can't divide by 0
Supreme Moderator
Joined: 01 Nov 2017
Posts: 370
Followers: 5

Kudos [?]: 111 [0], given: 4

Re: Which of the following is an equation of a line that doe NO [#permalink]  03 Dec 2018, 18:56
Expert's post
Carcass wrote:
Which of the following is an equation of a line that doe NOT contain any points in the xy-plane for which both coordinates are integers?

A.$$y=4$$

B. $$y=\frac{1}{2x}$$

C.$$y=x+3$$

D. $$y= x+\frac{1}{2}$$

E. $$y=\frac{1}{2x} + 3$$

The question or OA is flawed..
A.$$y=4$$.... x could be any integer...both integer possible

B. $$y=\frac{1}{2x}$$.......2xy=1 or xy=$$\frac{1}{2}$$..
If both x and y are integers, xy should be an integer... so both x and y cannot be integers

C.$$y=x+3$$... Possiible

D. $$y= x+\frac{1}{2}$$.......$$y- x=\frac{1}{2}$$..
The difference of two integers cannot be a fraction... so both x and y cannot be integers

E. $$y=\frac{1}{2x} + 3....y-3=\frac{1}{2x}$$........If x is an integer, $$\frac{1}{2x}$$ will be a fraction, then y-3 cannot be a fraction

so answer = B, D, and E

Note - editing the answer accordingly
_________________

Some useful Theory.
1. Arithmetic and Geometric progressions : https://greprepclub.com/forum/progressions-arithmetic-geometric-and-harmonic-11574.html#p27048
2. Effect of Arithmetic Operations on fraction : https://greprepclub.com/forum/effects-of-arithmetic-operations-on-fractions-11573.html?sid=d570445335a783891cd4d48a17db9825
3. Remainders : https://greprepclub.com/forum/remainders-what-you-should-know-11524.html
4. Number properties : https://greprepclub.com/forum/number-property-all-you-require-11518.html
5. Absolute Modulus and Inequalities : https://greprepclub.com/forum/absolute-modulus-a-better-understanding-11281.html

Manager
Joined: 01 Nov 2018
Posts: 87
Followers: 0

Kudos [?]: 43 [0], given: 22

Re: Which of the following is an equation of a line that doe NO [#permalink]  12 Feb 2019, 21:23
Expert's post
First, know that we have to get an integer for the x coordinate, and an integer for the y coordinate.

for Y = 4, and Y=x+3, we know the obvious answer,

for choice b

y=1/2x ... lets think..

0=1/2x... nope
y=1/[2(0)].... nope these answers are impossible.

lets try 1

1=1/(2x)

2x=1
then x = 1/2... so that doesn't work

y=1/2(1)

y=1/2... so no, that wont work.

try a bigger number, like 100

100=1/(2x)
200x=1
x=1/200....

try for x

y=1/[2(100)]
y=1/200.... nope still a fraction and integer pair. no matter what number you put, there will never be integers in both x and y coordinates.

For choice D
plug in any integer

1+1/2= 3/2
1000+ 1/2 = 2001/2.. no matter what you plug in, the number will always end in 1/2. so there will be no integer pairs for the x and y coordinates.

for E

thats just a continuation of B which was 1/(2x)
so, 1/(2x)+3 will always be a fraction, plus the number 3.

we choose B.D,E
Re: Which of the following is an equation of a line that doe NO   [#permalink] 12 Feb 2019, 21:23
Display posts from previous: Sort by