What is the remainder when a is divided by 4? (1) a is a square of an odd integer. (2) a is a multiple of 3. 2n+1 is considered as the odd integer so (2n+1)^2 (1) will have a remainder of 1 - SUFFICIENT (2) Insufficient. What i do not understand is if i consider the odd integer as 2n-1 then (2n-1)^2...

thanks! i missed the point of 0 and the remainder to be 1.