Question

Show that one and only one of n, n+2 and n+4 is divisibls by 3

Answer 1

let n is divisible by 3 and n/3=x

now

(n+2)/3= n/3+2/3=x+0.6667

thats what implying not exactly divisible by 3

due to decinal/fractional no.

similarly4/3