BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 1223
Joined: Sat Feb 15, 2020 2:23 pm
Followed by:1 members

The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?

by BTGModeratorVI » Tue Feb 16, 2021 8:21 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?

A. 10 and 20
B. 12 and 18
C. 24 and 32
D. 21 and 63
E. 22 and 88

Answer: C
Source: official guide
Top
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

Re: The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?

by Brent@GMATPrepNow » Fri Feb 26, 2021 6:01 am
BTGModeratorVI wrote: ↑
Tue Feb 16, 2021 8:21 am
 The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?

A. 10 and 20
B. 12 and 18
C. 24 and 32
D. 21 and 63
E. 22 and 88

Answer: C
Source: official guide
A. 10 and 20
10 = (2)(5)
20 = (2)(2)(5)
So, 10 and 20 both have 2 as a prime divisor, and they both have 5 has a prime divisor.
In other words, they have a PAIR a prime divisors in common
Eliminate A

B. 12 and 18
12 = (2)(2)(3)
18 = (2)(3)(3)
So, 12 and 18 both have 2 as a prime divisor, and they both have 3 has a prime divisor.
In other words, they have a PAIR a prime divisors in common
Eliminate B

C. 24 and 32
32 = (2)(2)(2)(2)(2)
So, 32 has only ONE distinct prime divisor
As such, it's impossible for 24 and 32 to have a PAIR a prime divisors in common

Answer: C

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8088
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

Re: The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?

by Scott@TargetTestPrep » Sun Mar 07, 2021 6:12 am
BTGModeratorVI wrote: ↑
Tue Feb 16, 2021 8:21 am
 The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?

A. 10 and 20
B. 12 and 18
C. 24 and 32
D. 21 and 63
E. 22 and 88

Answer: C
Source: official guide
Solution:

Let’s consider each of the answer choices:

A) The GCF of 10 and 20 is 10, which is 2 times 5. So 10 and 20 do have a pair of distinct prime divisors in common.

B) The GCF of 12 and 18 is 6, which is 2 times 3. So 12 and 18 do have a pair of distinct prime divisors in common.

C) The GCF of 24 and 32 is 8, which is 2^3. So 24 and 32 do NOT have a pair of distinct prime divisors in common.

Answer: C

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Post new topic Post Reply
• Page 1 of 1