NDA || Mathematics || Probability ||Quiz

In a multiple-choice test, an examinee either knows the correct answer with probability p or guesses with probability  The probability of answering a question correctly is  if he or she merely guesses. If the examinee answers a question correctly, the probability that he or she really knows the answer is

Five sticks of length 1, 3, 5, 7 and 9 feet are given. Three of these sticks are selected at random. What is the probability that the selected sticks can form a triangle?

Consider the following statements:

1)

2)

3) P(A ∩ B) = P(B) P(A | B)

Which of the above statements are correct?

Tickets numbered from 1 to 12 are mixed up together, and then a ticket is withdrawn at random. Find the probability that the ticket has a number which is a multiple of 2 or 3 .

In class, 30% of the students offered mathematics 20% offered chemistry and 10% offered both. If a student is selected at random, find the probability that he has offered mathematics or chemistry.