Find the remainder when 2^31 is divided by 5.  Choose the correct choice from the following answers
A) 3  B) 7  C) 1  D) 9  E) none of them

Rationale: 2 ^ 10 = 1024 . unit digit of 2 ^ 10 x 2 ^ 10 x 2 ^ 10 is 4 [ as 4 x 4 x 4 gives unit digit 4 ] . unit digit of 231 is 8 . now , 8 when divided by 5 , gives 3 as remainder . hence , 231 when divided by 5 , gives 3 as remainder . answer is a .
Answer: A