The following table shows the blood groups of 40 students of a class.
Blood groupABOABNumber of students119146
One student of the class is chosen at random. What is the probability that the chosen studet has blood group (i) O? (ii) AB?
ANSWER:
Total number of students = 40
(i) Number of students with blood group O = 14
Let E 1 be the event that the selected student's blood group is O.
∴ Required probability = P ( E 1 ) = 1440 = 0.35
(ii) Number of students with blood group AB = 6
Let E 2 be the event that the selected student's blood group is AB.
∴ Required probability = P ( E 2 ) = 640 = 0.15