Asmall start-up company with 15 employees will select its 4 board members from among the employees. how many different groups of board members are possible?

Because the order of people does not matter, we can use a permutation to find the answer. 

For the first choice there are 15 possible people. For the second one there are 14 possibilities (since one person has already been chosen) and so on. 

To get the total number of combinations we do: 

A: 18/15b : 7 - -8 = 15 , 12 - -6 = 18 the y variable always goes over the x variables, c : same thing a