problem with my array question

Hi i am back with another question :)....

6.10 Use a single subscript array to sove the following problem.A company pays its sales people on a comision basis.The salespeople recive $200 per week plus 9 percent of their gross sales for that week.For example, a salesperson whos grosses $3000 in sales in a week receives $200 plus 9 percent of $3000, or a total of $470.Write a c program ( ussing a counter of arrays) that determines how many of the salespeople earned salaries in each of the following ranges ( assume that each salesperson's salary is truncated to an integer amount).

1.200-299

2.300-399

3.400-499

4.500.599

and so on ..

Okay the question is.What do they mean by Using a counter of arrays and assume that each persons salary is truncated to an integer amount.