What is the greatest common factor of positive integers x and y?

This topic has expert replies
Source: — Data Sufficiency |

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 am
Location: Grand Central / New York
Thanked: 470 times
Followed by:34 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

BTGmoderatorDC wrote:
Mon Jun 08, 2020 6:44 pm
What is the greatest common factor of positive integers x and y?

(1) x and y share only one common factor.
(2) x and y are unique prime numbers.

OA D

Source: Veritas Prep
Let's take each statement one by one.

(1) x and y share only one common factor.

Note that all positive integers have 1 as a common factor. Since x and y share ONLY one common factor, they must be co-prime to each other. So, the greatest common factor of positive integers x and y = 1. Sufficient.

(2) x and y are unique prime numbers.

=> x and y are co-prime to each other. So, the greatest common factor of positive integers x and y = 1. Sufficient.

The correct answer: D

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: GMAT Classes | GMAT Tutoring | GRE Tutoring | LSAT Tutoring | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.