What is my Locker Combination?

Appeared in Volume 8/4, November 1995

1. My locker combination is made up of three numbers.

2. The numbers on the dial range from 1-40.

3. The second number is twice the first.

4. The third number is ten more than the second.

5. The first number has one even digit and one odd digit.

6. The second number has either two odd or two even digits.

7. The total of all the different digits used in the combination is 10. (For example: 22/22/22 would total 2, and 18/28/12 would total 11.)

Second: Is there any way to rewrite this puzzle with 6 or less rules, without the answer being obvious?

Eli Rubin
cr486@cleveland.freenet.edu