[Class of 11]

In the construction of a frequency distribution, the overlapping class limits ......

A) 10-20, 20-30, 30-40
B)9.5-19.5, 19.5-29.5, 29.5-39.5
C)10-20, 21-31, 32-42
D)10-20, 21-31, 32 and above

the right answer is A) 10-20, 20-30, 30-40

ما فهمت السؤال ولا الإجابة لأنه أكثر من جواب فيه overlapping class limits