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Remainder Problem

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Source: — Problem Solving |

by manpsingh87 » Sat Apr 16, 2011 5:37 am
taneja.niks wrote:If n is a positive integer, what is the remainder when 3^(8n+3) + 2 is divided by 5?

A. 0
B. 1
C. 2
D. 3
E. 4
3 repeats its last digit after every cycles, so when we divide 3^(8n+3) by remainder will always be 3, therefore last digit of the expression 3^(8n+3) would be 7, and last digit of the whole expression would be 3^(8n+3)+2=9, we know that remainder of a number when divided by 5 depends upon its last digit, for e.g. if 43 is divided by 5 remainder will be 3, similarly here remainder will be 9/5=4 hence answer should be E
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by Anurag@Gurome » Sat Apr 16, 2011 5:38 am
taneja.niks wrote:If n is a positive integer, what is the remainder when 3^(8n+3) + 2 is divided by 5?

A. 0
B. 1
C. 2
D. 3
E. 4
Has been discussed earlier also. See the thread: https://www.beatthegmat.com/mgmat-remainder-t78873.html
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

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