Consider the following frequency distribution:
Class | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
Frequency | 3 | 9 | 15 | 30 | 18 | 5 |
The modal class is
(a) 10-20 (b)20-30 (c)30-40 (d) 50-60
As the class 30-40 has maximum frequency, so it is the modal class.
Hence correct answer is option (C).