15 students ask to visit a college admissions counselor. Each visit includes one student. In how many ways can 10 time slots be assigned?

Question

dumbcow · Answer

permutations

15!/5!

anonymous · Answer

how do you get the 5?

anonymous · Answer

$$ 15^{\underline{10}} $$

anonymous · Answer

For the first time slot there are 15 students to assign it to, thus 15 possebilities, then 14 students left, and so on until 10 students have been assigned a time slot. 

This means 15*14*13*12*11*10*9*8*7*6

Or simply $$15! /5!$$ which means the same thing

dumbcow · Answer

its the formula for Permutations

nPr = n!/(n-r)!

in this case, n=15 r=10

anonymous · Answer

so why is it not 15!/10!

dumbcow · Answer

because of the reasoning Prebz described  ^^

anonymous · Answer

because then you will be not counting many possible cases.

anonymous · Answer

ok i think i get it now, i got very confused because we're supposed to just plug the first two numbers ( 15 and 10) in the formula in our calculator