Question

The blood groups of 30 students of class iX 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

A student is selected at random from the class from blood donation. Find the probability that the blood group of the student chosen is :

A. A

B. B

C. AB

D. O

Answer 1

Given,

Probability of a student of blood group A \(=\frac{favourable\,outcome}{total\, outcome}\)

\(=\frac{9}{30}=0.3\)

Probability of a student of blood group B \(=\frac{favourable\,outcome}{total\, outcome}\)

\(=\frac{6}{30}=0.2\)

Probability of a student of blood group AB \(=\frac{favourable\,outcome}{total\, outcome}\)

\(=\frac{3}{30}=0.1\)

Probability of a student of blood group O \(=\frac{favourable\,outcome}{total\, outcome}\)

\(=\frac{12}{30}=0.4\)