How many three digits odd numbers can be formed from the
digits 0,1,2,3 and 4? Repetition of digits is not allowed?
Always choose the most restricted quantities first.
Restrictions:
The first digit cannot be 0, but can only be 1,2,3 or 4.
The last digit can only be 1 or 3.
We choose the last digit 2 ways.
That leaves 3 ways to choose the first digit.
That leaves 3 ways to choose the middle digit.
Answer 2*3*3 = 18 ways.
1. 103
2. 123
3. 143
4. 201
5. 203
6. 213
7. 231
8. 241
9. 243
10. 301
11. 321
12. 341
13. 401
14. 403
15. 413
16. 421
17. 423
18. 431
Edwin