In a class of 40 students, 18 passed mathematics, 19 passed accounts, 16 passed economics, 5 passed mathematics and account only. Is each student offered at least only one subject,
(A how many students failed in all the subjects?
(B find the percentage number who failed in at least one if the economics and mathematics
(C calculate the probability that a student selected at random failed in accounts
(A) To find out how many students failed in all subjects, we need to subtract the number of students who passed each subject from the total number of students.
Total number of students = 40
Number of students who passed mathematics = 18
Number of students who passed accounts = 19
Number of students who passed economics = 16
Number of students who passed mathematics and accounts only = 5
Number of students who failed in all subjects = 40 - (18 + 19 + 16 - 5) = 40 - 48 + 5 = 5
Therefore, 5 students failed in all subjects.
(B) To find the percentage of students who failed in at least one subject if they passed economics and mathematics, we need to calculate the total number of students who passed either of the two subjects and divide it by the total number of students and multiply by 100 to get the percentage.
Total number of students who passed economics or mathematics = 18 + 19 - 5 (students who passed both subjects) + 16 = 48
Percentage of students who failed = (5/40) * 100 = 12.5%
(C) To calculate the probability that a student selected at random failed in accounts, we need to consider the total number of students who failed in accounts and divide it by the total number of students.
Total number of students who failed in accounts = 40 - 19 = 21
Total number of students = 40
Probability of failure in accounts = 21/40 = 0.525 or 52.5%