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.
May 2808:30 AM PDT
-09:30 AM PDT
Are you constantly rereading GMAT RC passages but still struggling to understand them? Most students think rereading improves accuracy — but in reality, it usually signals a flawed reading strategy.
May 2110:00 AM EDT
-11:59 PM EDT
Make the most of your break with the most realistic GMAT™ prep. Take up to $700 off select products.- May 27
08:30 AM PDT
-09:30 AM PDT
Next - GMAT Ninja CR series, we tackle a very specific flavor of Critical Reasoning: Plans & Goals questions. The GMAT loves to present a scenario where a company, government, or individual proposes a seemingly brilliant plan to achieve a specific goal. - Jun 10
06:00 AM PDT
-06:15 PM PDT
Register for the GMAT Club Virtual MBA Spotlight Fair – the world’s premier event for serious MBA candidates. This is your chance to hear directly from Admissions Directors at nearly every Top 30 MBA program..
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
55%
(hard)
Question Stats:
47% (01:09) correct
53%
(01:39)
wrong
based on 209
sessions
History
Date
Time
Result
Not Attempted Yet
If m and n are positive integers. What is the units digit of p^(m*n) ?
(1) The units digit of p^m is 1
(2) The units digit of p^n is 1
Can somebody please explain ?
Thanks
(1) The units digit of p^m is 1
(2) The units digit of p^n is 1
Can somebody please explain ?
Thanks
23 Jul 2013, 15:14
Kudos
Bookmarks
If m and n are positive integers. What is the units digit of p^(m*n) ?
(1) The units digit of p^m is 1 --> \(p^{(m*n)}=(p^m)^n=(...1)^m\) --> the units digit of \((...1)^m\) is 1. Sufficient.
(2) The units digit of p^n is 1 --> \(p^{(m*n)}=(p^n)^m=(...1)^n\) --> the units digit of \((...1)^n\) is 1. Sufficient.
Answer: D.
P.S. Please read carefully and follow: rules-for-posting-please-read-this-before-posting-133935.html Pay attention to the rule #3. Thank you.
(1) The units digit of p^m is 1 --> \(p^{(m*n)}=(p^m)^n=(...1)^m\) --> the units digit of \((...1)^m\) is 1. Sufficient.
(2) The units digit of p^n is 1 --> \(p^{(m*n)}=(p^n)^m=(...1)^n\) --> the units digit of \((...1)^n\) is 1. Sufficient.
Answer: D.
Theory on Exponents: math-number-theory-88376.html
DS Exponents questions to practice: search.php?search_id=tag&tag_id=39
PS Exponents questions to practice: search.php?search_id=tag&tag_id=60
Tough and tricky DS exponents and roots questions with detailed solutions: tough-and-tricky-exponents-and-roots-questions-125967.html
Tough and tricky PS exponents and roots questions with detailed solutions: tough-and-tricky-exponents-and-roots-questions-125956.html
DS Exponents questions to practice: search.php?search_id=tag&tag_id=39
PS Exponents questions to practice: search.php?search_id=tag&tag_id=60
Tough and tricky DS exponents and roots questions with detailed solutions: tough-and-tricky-exponents-and-roots-questions-125967.html
Tough and tricky PS exponents and roots questions with detailed solutions: tough-and-tricky-exponents-and-roots-questions-125956.html
P.S. Please read carefully and follow: rules-for-posting-please-read-this-before-posting-133935.html Pay attention to the rule #3. Thank you.
23 Jul 2013, 15:20
Kudos
Bookmarks
gepetow
hi,
\(p^(m*n)\)= \(p^m^n\) or \(p^n^m\)==> it can be written in both ways...
statement 1: unit digit of\(p^m=1\)
now clearly since p^m==>has unit digit 1 then p^m^n===>will also have unit digit 1
sufficient.
statement 2: The units digit of\(p^n\) is 1
then \(p^n^m\)==>this will have unit digit as one...as both means the same number..as shown above.
sufficient
hence D
please refer to below rules .
Attachments
exponent-rules.gif [ 16.63 KiB | Viewed 3919 times ]
