Let, three two digit consecutive numbers are, 15, 16, and 17.
The arithmetic mean of these three numbers are,
                    Summation of the three numbers ÷ 3
Therefore,
Summation of the three numbers = 15 + 16 + 17
                    = 48
Therefore,
The Arithmetic Mean of the three numbers = 48 ÷ 3
                        = 16
Therefore, it can be seen that the arithmetic mean of the three consecutive numbers are 16, which is one of the numbers that have been taken initially.