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.
Jul 1206:30 AM PDT
-08:30 AM PDT
Join our webinar to master GMAT RC Main Point Questions! Learn effective strategies to decipher passage themes and purposes. Senior Verbal Expert- Sunita Singhvi will equip you with tools to navigate complexities and avoid common traps set by the GMAT.
Jul 0901:00 PM EDT
-02:00 PM EDT
More Target Test Prep students are earning 100th percentile GMAT scores. Don’t settle for less when the Target Test Prep course gives you everything you need to score high on the GMAT. Start your 5-day free trial today.
Jul 1311:00 AM EDT
-12:30 PM EDT
Looking for your GMAT motivation to break through the score plateau? Pragati improved her score by massive 160 points with strategic guidance and hard-work! Find out how personalized mentorship and a strong mindset can turn GMAT struggles into success.
Jul 1508:00 PM PDT
-09:00 PM PDT
Full-length FE mock with insightful analytics, weakness diagnosis, and video explanations!
Jul 1611:00 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.
09 Jun 2024, 23:21
Kudos
Bookmarks
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
65%
(hard)
Question Stats:
58% (01:56) correct
42%
(01:45)
wrong
based on 231
sessions
History
Date
Time
Result
Not Attempted Yet
If x and y are positive integers, which of the following cannot be the highest common factor of 21x and 35y?
A. 7
B. 21
C. x - y
D. x + y
E. 21y
Source: Experts' Global
A. 7
B. 21
C. x - y
D. x + y
E. 21y
Source: Experts' Global
10 Jun 2024, 00:28
Kudos
Bookmarks
LamboWalker
If x and y are positive integers, which of the following cannot be the highest common factor of 21x and 35y?
A. 7
B. 21
C. x - y
D. x + y
E. 21y
Source: Experts' Global
21x = 7(3x) and 35y = 7(5y). Thus, the highest common factor of the two numbers must include 7.A. 7
B. 21
C. x - y
D. x + y
E. 21y
Source: Experts' Global
Let's check the options:
A. 7
For 7 to be the HCF of 7(3x) and 7(5y), 3x and 5y must be co-prime; they should not share any common factor except 1. Consequently, since 3 and 5 are already co-prime, x and y should be co-prime. For example, if x = 1 and y = 1, 7 would be the HCF of 21 and 35.
B. 21
If y is a multiple of 3 (and it does not share a common factor with x), then 21 will be the HCF of 7(3x) and 7(5y). For example, consider x = 1 and y = 3.
C. x - y
This could happen, for example, when x and y are co-prime such that x is not a multiple of 5 and y is not a multiple of 3, and x - y = 7. For example, consider x = 8 and y = 1.
D. x + y
Similarly, this could happen, for example, when x and y are co-prime such that x is not a multiple of 5 and y is not a multiple of 3, and x + y = 7. For example, consider x = 6 and y = 1.
E. 21y
21y cannot be the HCF since it's not a factor of 35y: 35y/(21y) = 5/3, which is not an integer.
Answer: E.
General Discussion
01 Jul 2025, 22:25
Kudos
Bookmarks
Please edit the question ;
21x and 35y it can be x&y unit digits
21x and 35y it can be x&y unit digits
