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.
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
Re: Which of the following could be the greatest common factor of positive
[#permalink]
Show Tags
28 Jan 2017, 07:50
Raahan wrote:
Bunuel wrote:
pepo wrote:
which of the following could be the greatest common factor of positive integers a and b?
I. 1 II. a III. a-b
A) II only B) I and II only C) I and III only D) II and III only E) I, II and III
It could be 1 if a and b are co-prime, for example, 1 and 2, 11 and 13...
It could be a itself if a is a factor of b, for example, 2 and 4, 5 and 15...
It could be a-b, for example, when a=b+1: a=2 and b=1, a=3 and b=2...
Answer: E.
Since greatest is asked it should be a single number not 3 numbers. Correct me if I'm wrong
The question asks which of the following could be the greatest common factor (GCF) of positive integers a and b? All three (for different cases) could be the greatest common factors of a and b. So, the answer is E.
_________________
Which of the following could be the greatest common factor of positive
[#permalink]
Show Tags
31 May 2017, 20:42
1
sasidharrs wrote:
The GCF of 4,10 is 2, which does not fall into any of the 3 categories right?
csaluja wrote:
Hi,
I am confused with the second option. If a and b were 2 and 3, their GCF would have been 1. How is second option still sufficient? Please explain!
Thanks!
Notice that the question asks "Which of the following COULD be the greatest common factor of positive integers a and b?" NOT "Which of the following MUST be the greatest common factor of positive integers a and b?"
_________________
Re: Which of the following could be the greatest common factor of positive
[#permalink]
Show Tags
01 Jun 2017, 06:58
Bunuel wrote:
sasidharrs wrote:
The GCF of 4,10 is 2, which does not fall into any of the 3 categories right?
csaluja wrote:
Hi,
I am confused with the second option. If a and b were 2 and 3, their GCF would have been 1. How is second option still sufficient? Please explain!
Thanks!
Notice that the question asks "Which of the following COULD be the greatest common factor of positive integers a and b?" NOT "Which of the following MUST be the greatest common factor of positive integers a and b?"
I see now, makes a lot of sense! Thanks a lot Bunuel!!
Re: Which of the following could be the greatest common factor of positive
[#permalink]
Show Tags
04 Dec 2017, 13:55
1
Hi All,
We're told that A and B are positive integers. We're asked which of the Roman Numerals COULD be the Greatest Common Factor of A and B. We can solve the problem by TESTing VALUES.
I. 1
IF A=1 and B=2, then the GCF = 1. Roman Numeral 1 COULD be true. Eliminate Answers A and D.
II. A
IF A=1 and B=2, then the GCF = 1 (so the GCF = A). Roman Numeral 2 COULD be true. Eliminate Answer C.
III. A - B
IF A=2 and B=1, then the GCF = 1 (so the GCF = A-B). Roman Numeral 3 COULD be true. Eliminate Answer B.
Which of the following could be the greatest common factor of positive
[#permalink]
Show Tags
11 Jan 2018, 15:22
pepo wrote:
Which of the following could be the greatest common factor of positive integers a and b?
I. 1 II. a III. a-b
A) II only B) I and II only C) I and III only D) II and III only E) I, II and III
The main thing to notice is COULD
1. Can it be 1? Yes if both the numbers are prime 2 Can it be a? Yes is a=2 and b=4 ..GCF is 2 3. Can it be a-b? Yes, if a=8 and b=4. the GCF is 4. a-b is also equal to 4
gmatclubot
Which of the following could be the greatest common factor of positive &nbs
[#permalink]
11 Jan 2018, 15:22
close
54% (00:37) correct 
