|
|
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.
15 Jan 2017, 09:15
Kudos
Bookmarks
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
5%
(low)
Question Stats:
80% (00:37) correct
20%
(00:50)
wrong
based on 193
sessions
History
Date
Time
Result
Not Attempted Yet
What is the remainder when the number 14^2*15^8 is divided by 5?
A. 0
B. 1
C. 2
D. 4
E. 5
A. 0
B. 1
C. 2
D. 4
E. 5
Updated on: 19 Jan 2017, 17:23
Originally posted by OptimusPrepJanielle on 15 Jan 2017, 13:45.
Last edited by OptimusPrepJanielle on 19 Jan 2017, 17:23, edited 1 time in total.
Last edited by OptimusPrepJanielle on 19 Jan 2017, 17:23, edited 1 time in total.
Kudos
Bookmarks
Bunuel
Last digit of 14^2 = 6
Last digit of 15^8 = 5
Last digit of multiplication = 0
Hence the remainder when (14^2)*(15^8) is divided by 5 = 0
Other way:
14^2*15^8 = 14^2*3^8*5^8
Hence this will always be divisible by 5
Correct option: A
15 Jan 2017, 16:33
Kudos
Bookmarks
This post is not written properly. Since parentheses are needed to illustrate the exact operations.
In the current way written (14^2*15^8) it means: 14^{2*15^{8}}
The OptimusPrepJanielle gave a solution for (14^2)*(15^8) and this is perfectly divided by 5, since 15 is divided perfectly by 3, hence the quotient is an integer and the remainder 0. Which requires 0 operations.
The author should clarify what the right notation is.
In the current way written (14^2*15^8) it means: 14^{2*15^{8}}
The OptimusPrepJanielle gave a solution for (14^2)*(15^8) and this is perfectly divided by 5, since 15 is divided perfectly by 3, hence the quotient is an integer and the remainder 0. Which requires 0 operations.
The author should clarify what the right notation is.
