the same as Shankar suggests - identify the pattern BUT 3^(4n + 2) is actually equal to 9^(2n+1) OR 9*9^(2n). It's clear that for any n you get even number in the powers, hence 9^(2n) will always have the unit's digit of 1 (because of cycles => 9^2=81, 9^4=...1, etc.)
now 9*9^(2n) will return the unit's digit 9. When m=1 we have the new unit's digit=0 and the number divisible by 10.
solved as such and the answer is B.
rohit_gmat wrote:n and m are positive integers, what is remainder when 3^(4n + 2) + m is divided by 10?
a. n = 2
b. m = 1
OA B
[spoiler]Need to know if there is any rule about 2(2N + 1)?[/spoiler]
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