Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Jul 1011:00 AM PDT
-11:00 AM PDT
In our conversation, Kishore talks about how strategically he used data analytics to identify high impact areas to focus on as well as his early morning study routine (3 AM prep!) that optimized his GMAT preparation.- Jun 30
08:00 AM PDT
-11:59 PM PDT
Join us June 30th for 2 weeks of GMAT questions (just 8 per day) to help with your prep and to compete with your fellow GMAT Clubbers for a chance to win a prize fund of $30,000 for you and your team-mates! 
Jul 0901:00 PM EDT
-02:00 PM EDT
More Target Test Prep students are earning 100th percentile GMAT scores. Don’t settle for less when the Target Test Prep course gives you everything you need to score high on the GMAT. Start your 5-day free trial today.
Jul 1206:30 AM PDT
-08:30 AM PDT
Join our webinar to master GMAT RC Main Point Questions! Learn effective strategies to decipher passage themes and purposes. Senior Verbal Expert- Sunita Singhvi will equip you with tools to navigate complexities and avoid common traps set by the GMAT.
Jul 1211:00 AM IST
-01:00 PM IST
Attend this session to learn how to Deconstruct arguments, Pre-Think Author’s Assumptions, and apply Negation Test.
Jul 1311:00 AM EDT
-12:30 PM EDT
Looking for your GMAT motivation to break through the score plateau? Pragati improved her score by massive 160 points with strategic guidance and hard-work! Find out how personalized mentorship and a strong mindset can turn GMAT struggles into success.
Jul 1508:00 PM PDT
-09:00 PM PDT
Full-length FE mock with insightful analytics, weakness diagnosis, and video explanations!
Jul 1611:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors.
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
25%
(medium)
Question Stats:
78% (01:55) correct
22%
(02:02)
wrong
based on 477
sessions
History
Date
Time
Result
Not Attempted Yet
What is the value of \((a! + b!)(c! + d!)\)?
(1) \(b!d! = 4(a!d!)\)
(2) \(60(b!c!) = (b!d!)\)
(1) \(b!d! = 4(a!d!)\)
(2) \(60(b!c!) = (b!d!)\)
09 Jun 2011, 12:04
Kudos
Bookmarks
AnkitK
whAT is the value of (a!+b!)(c!+d!)?
1.b!d!=4(a!d!)
2.60(b!c!)=(b!d!)
1.b!d!=4(a!d!)
2.60(b!c!)=(b!d!)
@sudhir18n: As per your request, giving the solution of this question. Your approach was correct but you overlooked one important point. Let me explain.
The question isn't as straight forward as some of you may believe. The trick here is the factorials and that n! can take only a limited set of values.
To get (a!+b!)(c!+d!), we need the values of all - a!, b!, c! and d!
Stmnt 1: b!d!=4(a!d!)
b! = 4*a!
Certainly, a can only be 3 and b can only be 4. There is no other way that this relation will hold.
Think of it this way
1*2*3*... = 4*(1*2*3*....)
4 has to be the last number multiplied on the left side.
Hence, b! = 4! and a! = 3!
No information about c and d so not sufficient.
Stmnt 2: 60(b!c!)=(b!d!)
60*c! = d!
Now this is a little trickier. c! could be 59! and d! could be 60! but
60 = 3*4*5, which leads us to another value of c and d.
c! could be 2! and d! could be 5!
3*4*5 *2! = 5!
Hence we got two different values for c! and d!
Not sufficient.
Using both statements together, we still do not know c and d, hence together also, they are not sufficient.
Answer (E)
General Discussion
10 May 2011, 10:44
Kudos
Bookmarks
AnkitK
whAT is the value of (a!+b!)(c!+d!)?
1.b!d!=4(a!d!)
2.60(b!c!)=(b!d!)
1.b!d!=4(a!d!)
2.60(b!c!)=(b!d!)
1.
b!*d!=4*a!*d!
Dividing both sides by d! as it is +ve;
b!=4a!
Not Sufficient.
2.
60*b!*c!=b!*d!
Dividing both sides by b! as it is +ve;
60*c!=d!
Not Sufficient.
(a!+b!)(c!+d!)
=5*a!*61*c!
=305*a!*c!
Not Sufficient.
Ans: "E"
