Question

In a medical examination of 40 students of a class, the following blood groups were recorded:

Blood group	A	B	AB	O
No. of students	11	15	9	5

From this group, a student is chosen at random. What is the probability that the chosen student's blood group is B?
(a) $\frac{3}{5}$

(b) $\frac{5}{8}$

(c) $\frac{3}{5}$

(d) $\frac{8}{3}$

Answer 1

(a) $\frac{3}{8}$

Explanation:
Total number of students = 40
Number of students with blood group B = 15

Let E be the event that the selected student's blood group is B.

∴ Required probability = P(E) = $\frac{15}{40}=\frac{3}{8}$

1440 = 0.35