To calculate the total number of possible excursion combinations, we need to find the product of the number of options for each day.
So, for Tuesday, there are 6 options. For Wednesday, there are 8 options. For Thursday, there are 7 options. And for Friday, there are 4 options.
The total number of possible excursion combinations is:
6 x 8 x 7 x 4 = 1,344
Therefore, there are 1,344 possible excursion combinations for the vacation.