It is currently 12 Dec 2017, 14:05

Close

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
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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If p and q are integers, is pq + 1 even?

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

Hide Tags

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42571

Kudos [?]: 135384 [1], given: 12691

If p and q are integers, is pq + 1 even? [#permalink]

Show Tags

New post 21 May 2017, 10:16
1
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

86% (00:51) correct 14% (00:50) wrong based on 105 sessions

HideShow timer Statistics

Kudos [?]: 135384 [1], given: 12691

1 KUDOS received
Intern
Intern
avatar
B
Joined: 16 Apr 2017
Posts: 1

Kudos [?]: 1 [1], given: 9

If p and q are integers, is pq + 1 even? [#permalink]

Show Tags

New post 22 May 2017, 08:10
1
This post received
KUDOS
For PQ+1 to be even, product of P and Q must be odd. For the product to be odd, P and Q both must be odd.

Option1: When P is divided by 2 and reminder is 1, implies P is odd. But nothing is mentioned about Q, so Q can be either even or odd.
The statement is not sufficient.

Option2: When Q is divided by 6 and reminder is 1, implies Q is odd. But nothing is mentioned about P, so P can be either even or odd.
The statement is not sufficient.

1+2: P and Q both are ODD, hence the PQ+1 will be even.
The statement is sufficient.

So, the answer is 'C'.

Kudos [?]: 1 [1], given: 9

Intern
Intern
avatar
B
Joined: 26 Jan 2017
Posts: 32

Kudos [?]: 17 [0], given: 7

Re: If p and q are integers, is pq + 1 even? [#permalink]

Show Tags

New post 22 May 2017, 10:39
Is pq + 1 even -> is pq odd -> are p and q odd

% -> Modulus sign, tells us what the remainder is
p%2 -> 1 : Odd
p%6 -> 1 : 7,13,19,25,31,37... : Odd

Thus ans is C

Kudos [?]: 17 [0], given: 7

2 KUDOS received
Manager
Manager
avatar
S
Joined: 26 Jan 2016
Posts: 90

Kudos [?]: 40 [2], given: 29

Location: India
GMAT 1: 690 Q49 V36
GPA: 3.01
Reviews Badge CAT Tests
Re: If p and q are integers, is pq + 1 even? [#permalink]

Show Tags

New post 06 Jun 2017, 23:35
2
This post received
KUDOS
4
This post was
BOOKMARKED
mendheypriyanka wrote:
For PQ+1 to be even, product of P and Q must be odd. For the product to be odd, P and Q both must be odd.

Option1: When P is divided by 2 and reminder is 1, implies P is odd. But nothing is mentioned about Q, so Q can be either even or odd.
The statement is not sufficient.

Option2: When Q is divided by 6 and reminder is 1, implies Q is odd. But nothing is mentioned about P, so P can be either even or odd.
The statement is not sufficient.

1+2: P and Q both are ODD, hence the PQ+1 will be even.
The statement is sufficient.

So, the answer is 'C'.


Yes that is correct.

Kudos [?]: 40 [2], given: 29

Manager
Manager
User avatar
B
Joined: 05 Oct 2014
Posts: 51

Kudos [?]: 11 [0], given: 153

Location: India
Concentration: General Management, Strategy
GMAT 1: 580 Q41 V28
GPA: 3.8
WE: Project Management (Energy and Utilities)
Re: If p and q are integers, is pq + 1 even? [#permalink]

Show Tags

New post 21 Oct 2017, 03:32
Question says is (pq+1) even

We denote any even no as 2n & any odd no as (2n+1)

(1) says, p=2a+1 => p must be odd, we do not know the value of q. So, INSUFFICIENT

(2) says, q=6b+1 => q=2*3b+1 =>q=2c+1 => q must be odd, we do not know the value of b. So, INSUFFICIENT

Combining (1) + (2), p*q = Odd (Since O*O =O)

Thus, (pq+1) = Odd +1 = Even. Option C is correct

Kudos [?]: 11 [0], given: 153

Re: If p and q are integers, is pq + 1 even?   [#permalink] 21 Oct 2017, 03:32
Display posts from previous: Sort by

If p and q are integers, is pq + 1 even?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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®.