|
|
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.
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:
46% (01:09) correct
54%
(01:39)
wrong
based on 210
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
Pure algebraic questions like this one are no longer part of the GMAT Data Sufficiency syllabus.
For relevant Data Sufficiency questions, please check the Data Sufficiency forum:
Data Sufficiency Forum
Data Sufficiency Forum
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 4002 times ]
