Question 460851
Let the tens digit = 2k+1, an odd number, then the hundreds digit is 2k and the units digit 2k+2, where k is a natural number. These digits must satisfy the conditions: 10 < 2k+2k+1+2k+2 <20 Solving these inequalities we get:
10< 6k+3 <20 => 7< 6k <20 => 7/6< k <20/7 These inequalities are equivalent to the inequalities: 1< k <3, since k is a natural number we conclude that k=1, and the digits of our number are: 2k=4; 2k+1=5 and 2k+2=6.

Answer: The number is 456, which satisfy our conditions.