Question

prove that one of any three consecutive integer is divisible by 3

Answer 1

let numbers be a,a+d,a+2d
where d=1 (since nos are consecutive
)
sum of nos= 3a+3d =3 (a+d) which is divisible by 3

Answer 2

let three consecutive integer is n,n+1,n+2.
where n=3p and 'n' is a positive integer.
so in 1.case:n=3p
hence it is divisible by 3.
And no any other is divisible by 3.
hope this helps you