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

It is currently 22 Sep 2018, 13:55

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

For how many unique coordinate points (P, Q), such that P and Q are in

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

Hide Tags

Senior Manager
Senior Manager
User avatar
G
Status: You have to have the darkness for the dawn to come
Joined: 09 Nov 2012
Posts: 309
Daboo: Sonu
GMAT 1: 590 Q49 V20
GMAT 2: 730 Q50 V38
GMAT ToolKit User Reviews Badge CAT Tests
For how many unique coordinate points (P, Q), such that P and Q are in  [#permalink]

Show Tags

New post Updated on: 30 Mar 2017, 09:34
3
6
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

34% (01:25) correct 66% (03:05) wrong based on 67 sessions

HideShow timer Statistics

For how many unique coordinate points (P, Q), such that P and Q are integers, is it true that P^2 - Q^2 = 1155?

a) 16
b) 24
c) 32
d) 48
e) 64

_________________

You have to have the darkness for the dawn to come.

Give Kudos if you like my post


Originally posted by daboo343 on 30 Mar 2017, 09:30.
Last edited by Bunuel on 30 Mar 2017, 09:34, edited 1 time in total.
Renamed the topic and edited the question.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49303
For how many unique coordinate  [#permalink]

Show Tags

New post 30 Mar 2017, 09:34
daboo343 wrote:
For how many unique coordinate points (P, Q), such that P and Q are integers, is it true that P2 - Q2 = 1155?

a) 16
b) 24
c) 32
d) 48
e) 64


This is a copy of the following MGMAT question: https://gmatclub.com/forum/for-how-many ... 97167.html
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
B
Joined: 17 Jun 2018
Posts: 8
Re: For how many unique coordinate points (P, Q), such that P and Q are in  [#permalink]

Show Tags

New post 05 Jul 2018, 08:10
P^2-Q^2=(P+Q)(P-Q)=1155=3*5*7*11
We can think of this as two numbers multiply with each other, and we need to find out the different combination to make the multiple of these two numbers equal to 1155.
3,5,7,11 these 4 numbers can have 8 different combination to get 1155.
(1,3*5*7*11);(3,5*7*11);(5,3*7*11);(7,3*5*11);(11,3*5*7);(3*5,7*11);(5*7,3*11);(3*7,5*11)
These 4 numbers can also be negative, so we have another 8 different combination to get 1155.
So we totally have (8+8)*2 = 32 different unique combination.
Why we need to multiple by 2?
IF A*B=1155, the value is assigned to A can also be assigned to B. For example, 15*77 and 77*15, both equal to 1155, but they are different points on coordinate.
GMAT Club Bot
Re: For how many unique coordinate points (P, Q), such that P and Q are in &nbs [#permalink] 05 Jul 2018, 08:10
Display posts from previous: Sort by

For how many unique coordinate points (P, Q), such that P and Q are in

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

Events & Promotions

PREV
NEXT


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.