BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

difficult questions

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Legendary Member
Posts: 966
Joined: Sat Jan 02, 2010 8:06 amFollowed by: 21 members
Thanked: 230 times

by shankar.ashwin » Thu Nov 03, 2011 7:41 am
Statement 1:

a^2+b^2+c^2+d^2 = 0.

Since all the terms have an even power, none of them can be -ve. And sum of 4 +ve numbers cannot be 0.
So all the terms, a,b,c and d should be 0. Their product would be =0 (even) Sufficient.

Statement 2:

You can have 4 even numbers, even product
or 4 odd numbers, odd product. A IMO
Last edited by shankar.ashwin on Thu Nov 03, 2011 7:47 am, edited 1 time in total.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 966
Joined: Sat Jan 02, 2010 8:06 amFollowed by: 21 members
Thanked: 230 times

by shankar.ashwin » Thu Nov 03, 2011 7:44 am
sukh wrote:
If N is a positive integer, is N ! divisible by 66 ?
(1)N! is divisible by 11
(2)N! is divisible by 12
Statement 1:
Since 11 is a prime number N should be >11, for it to be divisible by 11. N! would contain (6*11) Hence would be divisible by 66. Sufficient.

Statement 2:

N! is divisible by 12.

N! could be 4! (or) 12!. One case its divisible by 66 and in the other its not. Insuff.

A IMO
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Community Manager
Posts: 1060
Joined: Fri May 13, 2011 6:46 amFollowed by: 52 members
Location: Utrecht, The Netherlands
Thanked: 318 times

by neelgandham » Thu Nov 03, 2011 7:49 am
Is the product abcd even?

(1)a^2 +b^2 +c^2 + d^2 = 0 square of a number is always >0. So, only one case exists - a=b=c=d=0 ! - Sufficient!

(2)a = b = c = d If a = b = c = d = Even, then product abcd is Even; If a = b = c = d = Odd, then product abcd is Odd - Insufficient

IMO A

__________________________________________

If N is a positive integer, is N ! divisible by 66 ? Rephrasing the question, Is N > 11 ?

(1)N! is divisible by 11 => N > 11 - Sufficient
(2)N! is divisible by 12 => N > 4 - Insufficient

IMO A
Anil Gandham
Welcome to BEATtheGMAT | Photography | Getting Started | BTG Community rules | MBA Watch
Check out GMAT Prep Now's online course at https://www.gmatprepnow.com/
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 416
Joined: Tue Aug 30, 2011 2:18 pmFollowed by: 9 members
Location: Delhi, India
Thanked: 13 times

by vaibhavgupta » Thu Nov 03, 2011 7:50 am
sukh wrote:Is the product abcd even? (1)a^2 +b^2 +c^2 + d^2 = 0 (2) a = b = c = d
plz expain in detail

If N is a positive integer, is N ! divisible by 66 ? (1)N! is divisible by 11 (2)N! is divisible by 12
One of the most basic rules that u keep in ur head is that a square of any non-imaginary i.e. without iota, will always be non negative. :)
If OA is A, IMO B
If OA is B, IMO C
If OA is C, IMO D
If OA is D, IMO E
If OA is E, IMO A

FML!! :/
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 608
Joined: Sun Jun 19, 2011 11:16 amFollowed by: 8 members
Thanked: 37 times

by saketk » Fri Nov 04, 2011 12:28 am
Vaibhav is correct. Anyways, GMAT never tests imaginary numbers so you are good to go.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1