Q13:
If n is a positive integer, what is the remainder when 3exp(8n+3) + 2 is divided by 5?
A. 0
B. 1
C. 2
D. 3
E. 4
any easy of solving this kind of problem
This topic has expert replies
In this problem just increase the power as much as you can
for example we can write the above example as
(3.3^(2(4n+1)) + 2)/5
=>( 3.9^(4n+1) + 2)/5
for first part as 9%5 = 4 and 4 ^4n+1is always a number with units digit as 4 hence remainder is 4 as 4n+1 is Odd
3* 4 = 12 & 12%5 = 2
Hence adding Both 2+2 = 4
Hence the remainder is 4
for example we can write the above example as
(3.3^(2(4n+1)) + 2)/5
=>( 3.9^(4n+1) + 2)/5
for first part as 9%5 = 4 and 4 ^4n+1is always a number with units digit as 4 hence remainder is 4 as 4n+1 is Odd
3* 4 = 12 & 12%5 = 2
Hence adding Both 2+2 = 4
Hence the remainder is 4