The blood groups of 30 students of Class VIII are recorded as follows:
A, B, O, O, AB, O, A, O, B, A, O, B, A, O, O,
A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O.
Represent this data in the form of a frequency distribution table. Which is the most common, and which is the rarest, blood group among these students?
you were asked to prepare a frequency distribution table regarding the blood groups of 30 students of a class. Use this table to determine the probability that a student of this class, selected at random, has blood group AB.

Question

Accepted Answer

Thus, from the table, the most common blood group is ‘O’ and the rarest blood group is ‘AB.’

Let $A$ be the event of selecting a student has AB blood group.

Total number of students $n (S) = 30 .$

Number of students have AB blood group $n (A) = 3 .$

Thus, the probability of the selected student has AB blood group $p (A) = \frac{n (A)}{n (S)} = \frac{3}{30} = \frac{1}{10} .$

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