B. The variable s represents the number of students in each class.
C. The coefficient 14 represents the number of classes in the 9th grade.
Step-by-step explanation:
The total number can be found by multiplying the number of the things with the number of people producing it. For example if 5 boys make 5 colored ropes the total number of ropes will be 5*5= 25.
In this question the combinations rule is used for variuos number of classes which are 14. Now we have to find the number of students which are s (s-1). Suppose s= 6 so the number of students would be 6(6-1) = 6(5) = 30
We will multiply the number of classes 14 with the number of students s(s-1) to get the total number of cards produced.
