480700. The different combinations of students that could go on the trip with a total of 25 student, but only 18 may go, is 480700.
The key to solve this problem is using the combination formula
. This mean the number of ways to choose a sample of r elements from a set of n distinct objects where order does not matter and replacements are not allowed.
The total of students is n and the only that 18 students may go is r:

Answer:
6 aend 7
Step-by-step explanation:
they got on more so leeaseea
Answer 0.24. i hope this is right
7.87 is what i got :) good luck!!