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 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.
Updated on: 13 Aug 2018, 01:56
Originally posted by EgmatQuantExpert on 27 Feb 2018, 10:01.
Last edited by EgmatQuantExpert on 13 Aug 2018, 01:56, edited 4 times in total.
Last edited by EgmatQuantExpert on 13 Aug 2018, 01:56, edited 4 times in total.
Kudos
Bookmarks
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
5%
(low)
Question Stats:
83% (00:47) correct
17%
(01:03)
wrong
based on 339
sessions
History
Date
Time
Result
Not Attempted Yet
e-GMAT Question:
If a and b are two positive numbers, what is the product of a and b?
1) The LCM of a and b is 16
2) The GCD of a and b is 4
A) Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B) Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C) BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D) EACH statement ALONE is sufficient.
E) Statements (1) and (2) TOGETHER are NOT sufficient.
This is
Question 1 of The e-GMAT Number Properties Marathon
Go to
27 Feb 2018, 11:07
Kudos
Bookmarks
EgmatQuantExpert
Statement 1: if a=1 & b=16, then LCM=16 & a*b=16. but is a=2 & b=16, then LCM =16 but a*b=2*16=32. Insufficient
Statement 2: if a=b=4, then HCF=4 & a*b=4*4=16 but if a=4 & b=8, GCD=4 but a*b=32. Insufficient
Combining 1 & 2: Product of two numbers = LCM*GCD. Sufficient
OPtion C
28 Feb 2018, 00:06
Kudos
Bookmarks
Solution:
Step 1: Analyse Statement 1:
The LCM of\(a\) and \(b\) is \(16\).
- Both a and b can have more than 1 combination for their LCM to be \(16\).
- For example, all the following combinations will have \(LCM (a, b) = 16\).
From the table, it is evident that there are more than 1 possible combinations of \(a\) and \(b\) where their LCM is \(16\). Hence, their product is also not unique.
Since this statement doesn’t give a unique answer, it is alone not sufficient to answer our question.
Statement 1 alone is NOT sufficient to answer the question.
Hence, we can eliminate answer choices A and D.
Step 2: Analyse Statement 2:
The HCF of \(a\) and \(b\) is \(4\).
- Both a and b can have more than 1 combination for their GCD to be \(4\).
- For example, all the following combinations will have \(GCD (a, b) = 4\).
From the table, it is evident that there are more than 1 possible combinations of a and b where their GCD is 4, and hence, their product is also not unique.
Since this statement doesn’t give a unique answer, it is alone not sufficient to answer our question.
Step 3: Combine both Statements:
- From the first Statement we got: \(LCM (a, b)\) = \(16\)
- From the second Statement we got:\(GCD (a, b)\) = \(4\)
Per our conceptual knowledge, we can say that the product of two numbers is the product of their LCM and GCD.- Hence, \(a * b\)= \(LCM (a, b) * GCD (a, b)\)
- Or, \(a*b\) = \(16*4\) = \(64\)
Correct Answer: Option C
