Answer:
150 (not sure)
Step-by-step explanation:
Paths that only touch 5 points unrepeatedly:
I used a tree diagram to list all the workable paths, taking cell A as an example:
- ABCDE
- ABCED
- ABECD
- ABEDC
- AEBCD
- AEDCB
- ADCBE
- ADCEB
- ADEBC
- ADECB
2*(3x2 - 1) = 10
When you start at A you would have 3 choices, but after that only two, and since DB or BD can't happen and crossing B and D for the second step is the same, I double it.
Paths that touch 5 points and reapeat one of them:
2*(3x2x2 - 1x2) = 20
Paths that touch 5 points and repeat two of them:
2*(3x2x2x2-1x2x2) = 40
Paths that touch 5 points and repeat three of them:
2*(3x2x2x2x2-1x2x2x2) = 80
The sum of the answers in these 4 senarios is the final answer.
150