GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 31 Mar 2020, 03:11 ### 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.  # If x are y are positive integers, what is the value of x+y

Author Message
TAGS:

### Hide Tags

Current Student D
Joined: 12 Aug 2015
Posts: 2537
Schools: Boston U '20 (M)
GRE 1: Q169 V154 If x are y are positive integers, what is the value of x+y  [#permalink]

### Show Tags

8 00:00

Difficulty:   35% (medium)

Question Stats: 61% (00:55) correct 39% (00:43) wrong based on 147 sessions

### HideShow timer Statistics

If x are y are positive integers, what is the value of x+y?
(1) x and y are consecutive prime numbers
(2) x-y=1

_________________
Retired Moderator V
Status: Long way to go!
Joined: 10 Oct 2016
Posts: 1298
Location: Viet Nam
Re: If x are y are positive integers, what is the value of x+y  [#permalink]

### Show Tags

1
s1d1 wrote:
If x are y are positive integers, what is the value of x+y?
(1) x and y are consecutive prime numbers
(2) x-y=1

from 1-2,3 are consecutive prime nos.
from2- many possibilities are there

hence A

The highlighted is not true. 3, 5 are consecutive prime numbers, 7, 11 are consecutive prime numbers

(1) or (2) can't lead to value of x + y.

Combine (1) and (2): only $$(x,y)=(3,2)$$ sufficient.

I've seen the same topic in gmatclub, if I'm not wrong _________________
Manager  G
Joined: 21 Jul 2017
Posts: 182
Location: India
GMAT 1: 660 Q47 V34
GPA: 4
WE: Project Management (Education)
Re: If x are y are positive integers, what is the value of x+y  [#permalink]

### Show Tags

1
Tip: Consecutive prime numbers doesn't imply only on the pair (2,3).
Intern  B
Joined: 07 May 2016
Posts: 23
Location: India
GMAT 1: 640 Q48 V28
GMAT 2: 690 Q48 V37
GPA: 2.95
WE: General Management (Other)
Re: If x are y are positive integers, what is the value of x+y  [#permalink]

### Show Tags

If x are y are positive integers, what is the value of x+y?
(1) x and y are consecutive prime numbers
(2) x-y=1

from 1- 2,3 are consecutive prime nos.
from2- many possibilities are there

hence A
_________________
-S1D1
Senior Manager  G
Joined: 06 Jul 2016
Posts: 351
Location: Singapore
Concentration: Strategy, Finance
Re: If x are y are positive integers, what is the value of x+y  [#permalink]

### Show Tags

stonecold wrote:
If x are y are positive integers, what is the value of x+y?
(1) x and y are consecutive prime numbers
(2) x-y=1

x,y > 0
x + y = ?

1) x, y -> consecutive primes
x = 2, y = 3
x + y = 5
x = 3, y = 5
x + y = 8
Insufficient.

2) x = y + 1
y = 1, x = 2
y = 2, x = 3
Insufficient.

1+2)
x = y + 1 & x,y are consecutive primes.
=> y = 2, x = 3
Sufficient.

_________________
Put in the work, and that dream score is yours!
Retired Moderator P
Joined: 19 Mar 2014
Posts: 910
Location: India
Concentration: Finance, Entrepreneurship
GPA: 3.5
Re: If x are y are positive integers, what is the value of x+y  [#permalink]

### Show Tags

If x are y are positive integers, what is the value of x+y?

(1) x and y are consecutive prime numbers

x and y can take values such as:

2, 3 = x + y = 2 + 3 = 5
3, 5 = x + y = 3 + 5 = 8
5, 7 = x + y = 5 + 7 = 12

As we are getting multiple values, this information is not sufficient.

Hence, (1) ===== is NOT SUFFICIENT

(2) $$x-y=1$$

Once again, x and y can take values such as:

3, 2 = x + y = 3 + 2 = 5
5, 4 = x + y = 5 + 4 = 9
7, 6 = x + y = 7 + 6 = 13

As we are getting multiple values, this information is not sufficient.

Hence, (2) ===== is NOT SUFFICIENT

Combining (1) & (2)

x and y are consecutive prime numbers and $$x-y=1$$

With above information, there is only one possibility

x = 3

y = 2

3 - 2 = 1

Hence, (1) & (2) ===== is SUFFICIENT

_________________
"Nothing in this world can take the place of persistence. Talent will not: nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not: the world is full of educated derelicts. Persistence and determination alone are omnipotent."

Best AWA Template: https://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html#p470475
GMAT Club Legend  V
Joined: 11 Sep 2015
Posts: 4551
GMAT 1: 770 Q49 V46
Re: If x are y are positive integers, what is the value of x+y  [#permalink]

### Show Tags

Top Contributor
stonecold wrote:
If x are y are positive integers, what is the value of x+y?

(1) x and y are consecutive prime numbers
(2) x - y = 1

Target question: What is the value of x+y?

Given: x are y are positive integers

Statement 1: x and y are consecutive prime numbers
This statement doesn't FEEL sufficient, so I'll TEST some values.
There are several values of x and y that satisfy statement 1. Here are two:
Case a: x = 2 and y = 3 (two consecutive primes), in which case x + y = 2 + 3 = 5
Case b: x = 19 and y = 23 (two consecutive primes), in which case x + y = 19 + 23 = 42
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Aside: For more on this idea of testing values when a statement doesn't feel sufficient, read this article: http://www.gmatprepnow.com/articles/dat ... lug-values

Statement 2: x - y = 1
There are several values of x and y that satisfy statement 2. Here are two:
Case a: x = 3 and y = 2, in which case x + y = 3 + 2 = 5
Case b: x = 5 and y = 4, in which case x + y = 5 + 4 = 9
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 1 tells us that x and y are consecutive primes
Statement 2 tells us that x and y differ by 1
If x and y differ by 1, then one number is ODD and the other is EVEN
Since there is only one EVEN prime number (2), then it must be the case that y = 2 and x = 3, in which case x + y = 3 + 2 = 5
Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Cheers,
Brent
_________________
Non-Human User Joined: 09 Sep 2013
Posts: 14453
Re: If x are y are positive integers, what is the value of x+y  [#permalink]

### Show Tags

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 x are y are positive integers, what is the value of x+y   [#permalink] 06 Jun 2019, 02:51
Display posts from previous: Sort by

# If x are y are positive integers, what is the value of x+y  