Answer:
15504 different groups
Step-by-step explanation:
We have a total of 20 people, and we want to know how many groups of 5 people we can make, where the order of the people inside the group doesn't matter, so we can solve this question calculating the combination of 20 choose 5.
The formula for combination is:
C(n, p) = n! / (p! * (n-p)!)
In this case, we have n = 20 and p = 5, so:
C(20, 5) = 20! / (5! * 15!) = 20*19*18*17*16 / (5*4*3*2) = 15504
So we have 15504 different groups.
The volume of this box is indeed 84 in^3. What were you looking for beyond that?
Base: (7 in)(3 in) = 21 in^2
Height: 4 in
volume = (21 in^2)(4 in) = 84 in^3 (answer)
Do you mean checking your work? In that case it would be 9*20.
30 minutes / 3 miles = 10 minutes for 1 mile
7 miles * 10 minutes per mile = 70 minutes total to run 7 miles