a test consists of 25 multiple choice questions. Each has 5 possible answers, which only one is correct. If a student guesses on each question, find the following:

a) prob that he will guess all of them right
b)prob that he will guess at most 12 right
c) prob that he will guess at least 1 right
d) mean and stndrd. deviation of the number of correct answers
e)estimate the prob of the number of correct answers that will fall within the limits -----> miu +or- 2(stand.dev)