Aprofessor must randomly select 4 students to participate in a mock debate. there are 18 students in his class. in how many different ways can these students be selected, if the order of selection does not matter?

a. 3,060
b. 38,390
c. 73,440
d. 1,768

The problem above makes use of the concept of combination because the order is not important in the selection. The mathematical expression of the given above is,
                                             18C4
which translates to "combination of 18 taken 4". The numerical value of the combination is 3060. Thus, the answer is letter A.