Prove that one of any three consecutive
Prove that one of any three consecutive positive integers must be divisible by 3.
Any three consecutive positive integers must be of the form
n, (n + 1)and (n + 2), where n is any natural number, i.e., n = 1,2, 3…
Let, a = n,b = n+ 1 and c = n + 2
Order triplet is (a, b, c) = (n, n + 1, n + 2), where n = 1,2, 3,… …(i)
At n = 1; (a, b, c) = (1,1 + 1,1 + 2) = (1,2, 3)
At n = 2; (a,b,c) = (1,2 + 1,2 + 2) = (2, 3, 4)
At n = 3; (a, b, c) = (3, 3 + 1, 3 + 2) = (3, 4, 5)
At n = 4; (a, b, c) = (4, 4 + 1, 4 + 2) = (4, 5, 6)
At n = 5; (a, b, c) = (5, 5 + 1, 5 + 2) = (5, 6,7)
At n= 8 (a, b, c) = (6, 6+ 1, 6 + 2) = (6,7, 8)
Atn = 7; (a, b, c) = (7,7 + 1,7 + 2) = (7, 8, 9)
At n = 8; (a, b, c) = (8 8 + 1, 8 + 2) = (8, 9,10)
We observe that each triplet consist of one and only one number which is multiple of 3 i.e., divisible by 3.
Hence, one of any three consecutive positive integers must be divisible by 3.