Given that there are 12 persons, the first choice may be in 12 different ways, the second choice may be in 11 different ways, ther third in 10 different ways, the fourth in 9 different ways and the fith in 8 different ways, for a total of:
12x11x10x9x8 different combinations.
Now you have to take in account that 5x4x3x2 are repetitions. So you have to divide the previos counting by 5x4x3x2.
(12x11x10x9x8)/(5x4x3x2) = 792 different subcommittees.
Also, you can use the formula for combinations: C(m,n) = m! / (n! (m-n)!)
If you know the radius of a circular track, you can use physics to calculate how fast an object needs to move in order to stay in contact with the track without falling when it reaches the top of the loop.
