The whole batch of calculators is rejected either if the first two chosen are both faulty if a third one needs to be chosen and it is faulty. or Calculate the probability that the whole batch is rejected.

Jack has just been given a ten-question multiple choice quiz in history class. Each question has five answers, of which only one is correct. Since Jack has not attended class recently, he does not know any of the answers. Assuming Jack guesses randomly on all ten questions, find the probability that he will answer six or more of the questions correctly and avoid an F.

Suppose that the population is 1000 people and the probability of cat people is 25% if we take a random sample of 100 people what is the probability that the proportion in the sample will be bigger than 29%

The probability that Mr. Johnson goes for an evening walk on any given day during the winter is 0.56.  Out of 89 days of winter, the number of days that Mr. Johnson is expected not to take an evening walk to the nearest day, is