The following data represent the fall 2009 student headcount enrollments for all public community colleges in the state of Illinois.
Number of Students Number of
Enrolled ........ Community Colleges
0–4,999 ........... 17
5,000–9,999 ........ 18
10,000–14,999 ........ 7
15,000–19,999 ........ 5
20,000–24,999 ........ 0
25,000–29,999 ........ 1
Find
(a) The number of classes,
(b) The class limits, and
(c) The class width.