If the remainder is 7 when positive integer n is divided by 10, what is the remainder when n is divided by 5? Pick one
A) 0 B) 1 C) 2 D) 3 E) 2

Rationale: "assume x is quotient here , n = 10 x + 7 - - - - - - - - - - ( 1 ) and n = 5 x + ? we can also write equation ( 1 ) as : n = ( 10 x + 5 ) + 2 . ie 5 ( 2 x + 1 ) + 1 ie the first term is perfectly divisible by 5 . so , the remainder left is 2 so , answer ( e ) is right choice ."
Answer: E