Answer:
24 ways
Step-by-step explanation:
1) In Combinatorics when we arrange a number and the order matter, we call it arrange the possibilities. For this exercise let's not use formulas but reasoning.
2) For this case we need a two figure number. Since we have seven numbers.
Since there is no repetition, all the possibilities are:
[tex]7*6=42[/tex]
3) But there is a restriction it's forbidden adjacent even and odd numbers: These numbers we don't want them:
13 15 17
24 26
31 35 37
42 46
51 53 57
62 66
71 73 75
18 non desirable results
The total arrangements minus the not possible combinations, will match the possible results:
[tex]42-18=24[/tex]
3) Just for checking, we have here the allowed combinations:
12 14 16
21 23 25 27
32 34 36
41 43 45 47
52 54 56
61 63 65 67
72 74 76
A total of 24 possible ways.
