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 1612:00 PM EDT
-11:59 PM EDT
You’re first to know: Save $200 on GMAT prep starting tomorrow, 4/13. Get 6 official practice tests and study with real questions. Be ready to save!
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.
13 Jul 2021, 02:45
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
15%
(low)
Question Stats:
82% (01:21) correct
18%
(01:34)
wrong
based on 335
sessions
History
Date
Time
Result
Not Attempted Yet
What is the units digit of the sum \(3^{47} + 5^{43} + 2^{12}\) ?
A. 2
B. 3
C. 5
D. 8
E. 9
A. 2
B. 3
C. 5
D. 8
E. 9
Updated on: 13 Jul 2021, 03:21
Originally posted by rajatchopra1994 on 13 Jul 2021, 02:55.
Last edited by rajatchopra1994 on 13 Jul 2021, 03:21, edited 1 time in total.
Last edited by rajatchopra1994 on 13 Jul 2021, 03:21, edited 1 time in total.
Kudos
Bookmarks
Explanation:
Unit digit for sum = 3^47+5^43+2^12
Cyclicity of 5 will be 5 always
Cyclicity of 3 will be 3,9,7,1
Cyclicity of 2 will be 2,4,8,6
Unit digit sum = 7 + 5 + 8
= 12 + 6 = 18
IMO-D
Unit digit for sum = 3^47+5^43+2^12
Cyclicity of 5 will be 5 always
Cyclicity of 3 will be 3,9,7,1
Cyclicity of 2 will be 2,4,8,6
Unit digit sum = 7 + 5 + 8
= 12 + 6 = 18
IMO-D
13 Jul 2021, 03:16
Kudos
Bookmarks
Cyclicity of 3 is 4 {3, 9, 7, 1}
Cyclicity of 5 is 1 {always units digit is 5 for positive power }
Cyclicity of 2 is 4 {2, 4, 8, 6}
nits digit of the sum \(3^{47} + 5^{43} + 2^{12}\) will be the unit digit of sum of units digits i.e 7 + 5 + 6 = 18 i.e 8
D is the answer
Cyclicity of 5 is 1 {always units digit is 5 for positive power }
Cyclicity of 2 is 4 {2, 4, 8, 6}
nits digit of the sum \(3^{47} + 5^{43} + 2^{12}\) will be the unit digit of sum of units digits i.e 7 + 5 + 6 = 18 i.e 8
D is the answer
Bunuel
