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 2301:30 AM EDT
-02:30 AM EDT
Struggling with GMAT Verbal as a non-native speaker? Harsh improved his score from 595 to 695 in just 45 days—and scored a 99 %ile in Verbal (V88)! Learn how smart strategy, clarity, and guided prep helped him gain 100 points.
Apr 2212:30 AM EDT
-01:30 AM EDT
At one point, she believed GMAT wasn’t for her. After scoring 595, self-doubt crept in and she questioned her potential. But instead of quitting, she made the right strategic changes. The result? A remarkable comeback to 695. Check out how Saakshi did it.
Apr 2308:00 PM PDT
-09:00 PM PDT
Video explanations + diagnosis of 10 weakest areas + 150+ short videos + study plan!
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 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
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.
16 Sep 2014, 00:44
Kudos
Bookmarks
If \(n\) is an non-negative integer, is \(10^n+8\) divisible by 18?
(1) \(n\) is a prime number.
(2) \(n\) is an even number.
(1) \(n\) is a prime number.
(2) \(n\) is an even number.
16 Sep 2014, 00:44
Kudos
Bookmarks
Official Solution:
If \(n\) is an non-negative integer, is \(10^n+8\) divisible by 18?
Observe that \(10^n+8\) is divisible by 18 for any positive integer value of \(n\). In this case, \(10^n+8=\text{even}+\text{even}=\text{even}\), so it's divisible by 2. Additionally, the sum of the digits of \(10^n+8\) is 9, so it's divisible by 9. Since \(10^n+8\) is divisible by both 2 and 9, it is also divisible by \(2*9=18\).
However, if \(n=0\), then \(10^n+8=1+8=9\), so in this case, \(10^n+8\) is not divisible by 18.
Therefore, the question essentially asks whether \(n\) is a positive integer.
(1) \(n\) is a prime number.
Since \(n\) is a prime number, it must be a positive integer. Sufficient.
(2) \(n\) is an even number.
\(n\) can be zero as well as any positive even number. Not sufficient.
Answer: A
If \(n\) is an non-negative integer, is \(10^n+8\) divisible by 18?
Observe that \(10^n+8\) is divisible by 18 for any positive integer value of \(n\). In this case, \(10^n+8=\text{even}+\text{even}=\text{even}\), so it's divisible by 2. Additionally, the sum of the digits of \(10^n+8\) is 9, so it's divisible by 9. Since \(10^n+8\) is divisible by both 2 and 9, it is also divisible by \(2*9=18\).
However, if \(n=0\), then \(10^n+8=1+8=9\), so in this case, \(10^n+8\) is not divisible by 18.
Therefore, the question essentially asks whether \(n\) is a positive integer.
(1) \(n\) is a prime number.
Since \(n\) is a prime number, it must be a positive integer. Sufficient.
(2) \(n\) is an even number.
\(n\) can be zero as well as any positive even number. Not sufficient.
Answer: A
General Discussion
07 May 2023, 05:12
Kudos
Bookmarks
I have edited the question and the solution by adding more details to enhance its clarity. I hope it is now easier to understand.
