Answer:
The students can group themselves in 360360 ways
Step-by-step explanation:
For this exercise we need to use the following equation:

This equation give us the number of assignation of n elements in k cell, where n1, n2, ..nk are the element that are in every cell
In this case we have 15 student that need to be assign in three vehicles with an specific capacity. This vehicles would be the equivalent to cells, so we can write the equation as:

Because the first vehicle have 7 seating, the second vehicle have 5 seating and the third vehicle have 3 seating.
Solving the equation we get 360360 ways to organized 15 students in three vehicles with capacity of 7, 5 and 3 seating.
Hi!
1. Your answer should be the first option. (It looks the best to me)
2. it is the last option because it's the only one that's identical to the original picture.
3. It should be the third option since there are 10cm on the top of the shape.
4. a total of 39
Hope that helps, good luck! :)
Answer:
Can you get a picture please or more detail...