Question

The blood groups of 30 students of a class are recorded as under:
A, B, O, O, AB, O, A, O, A, B, O, B, A, O, O, A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O.
(i) Represent this data in the form of a frequency distribution table.
(ii) Find out which is the most common and which is the rarest blood group among these students.

Answer 1

(i)

Blood group	tally marks	Number of students
A		9
B		6
O		12
AB		3

(ii) AB is rarest and O is most common.