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.
Apr 2711:00 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
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
55%
(hard)
Question Stats:
56% (01:34) correct
44%
(01:57)
wrong
based on 41
sessions
History
Date
Time
Result
Not Attempted Yet
Is y!/x! an integer?
(1) (x + y)(x-y) = 5! + 1
(2) x + y = 112
(1) (x + y)(x-y) = 5! + 1
(2) x + y = 112
This Question is Locked Due to Poor Quality
Hi there,
The question you've reached has been archived due to not meeting our community quality standards. No more replies are possible here.
Looking for better-quality questions? Check out the 'Similar Questions' block below
for a list of similar but high-quality questions.
Want to join other relevant Problem Solving discussions? Visit our Data Sufficiency (DS) Forum
for the most recent and top-quality discussions.
Thank you for understanding, and happy exploring!
13 Jul 2012, 04:47
Kudos
Bookmarks
This is a flawed question.
Is y!/x! an integer?
First of all, factorial is defined only for non-negative integers, so realistic GMAT question would mention that \(x\) and \(y\) are non-negative integers.
Next, \(\frac{y!}{x!}=integer\) will hold true if \(y\geq{x}\). So, the question basically asks whether \(y\geq{x}\).
(1) (x + y)(x-y) = 5! + 1 --> \(x^2-y^2=121\). As discussed, since \(x\) and \(y\) must be non-negative integers, then \(x>y\) and the asnwer to the question is NO. Sufficient.
(2) x + y = 112. Not sufficient to answer whether \(y\geq{x}\).
Answer: A.
Now, even though formal answer to the question is A, this is not a realistic GMAT question, as: on the GMAT, two data sufficiency statements always provide TRUE information and these statements never contradict each other. But from (1) the only non-negative integer solutions for \(x\) and \(y\) are: (11, 0) and (61, 60), so \(x+y\) cannot equal to 112 as the second statement says, which means that the statements clearly contradict each other.
The question is flawed. You won't see such a question on the GMAT.
Hope it's clear.
Is y!/x! an integer?
First of all, factorial is defined only for non-negative integers, so realistic GMAT question would mention that \(x\) and \(y\) are non-negative integers.
Next, \(\frac{y!}{x!}=integer\) will hold true if \(y\geq{x}\). So, the question basically asks whether \(y\geq{x}\).
(1) (x + y)(x-y) = 5! + 1 --> \(x^2-y^2=121\). As discussed, since \(x\) and \(y\) must be non-negative integers, then \(x>y\) and the asnwer to the question is NO. Sufficient.
(2) x + y = 112. Not sufficient to answer whether \(y\geq{x}\).
Answer: A.
Now, even though formal answer to the question is A, this is not a realistic GMAT question, as: on the GMAT, two data sufficiency statements always provide TRUE information and these statements never contradict each other. But from (1) the only non-negative integer solutions for \(x\) and \(y\) are: (11, 0) and (61, 60), so \(x+y\) cannot equal to 112 as the second statement says, which means that the statements clearly contradict each other.
The question is flawed. You won't see such a question on the GMAT.
Hope it's clear.
14 Oct 2012, 12:47
Kudos
Bookmarks
lrajiv74
y!/x! will be integer if y>=x
from 1. x^2-y^2 = positive value
Thus |x| > |y|
Since negative values cant have factorials. we have x>y . Hence it is NEVER an INTEGER. HENCE SUFFICIENT. Therefore A
Also, Please give answers ONLY in spoiler.
