12. (40 points) Dasha, Masha, and Sasha are coming up with various five-digit numbers in the decimal system that can be obtained from each other by rearranging the digits. Can it happen that the sum of the numbers thought of by Sasha and Masha is equal to twice the number thought of by Dasha?
Answer: Yes, it could.

Solution: For example, if Dasha came up with the number 10061, Masha the number 10016, and Sasha the number 10106.