The probability that a teacher will give an unannounced test during any class meeting is 1/5. If a student is absent twice, find the probability that the student will miss at least one test.

The probability that a teacher will give a surprise test during any class is 1/5. If a student is absent on two day what is the probability that he will miss atleast one test.

A dice is thrown twice. Find the probability of getting 3 at least one time.

A class has 20 girls and 16 boys. One student is selected at random. Find the probability that the student is a girl.

The probability to pass in an examination of mathematics for three students are 1/4,1/5,1/6 . Find the probability that at least two students will pass in this examination.

The probability that a student is not a swimmer is 1/5. Then find the probability that out of 5 students exactly 4 are swimmer.

The cumulative histrogram above shows the distribution of scores that 24 students received on an English test. If a students is selected at random, what is the probability that the student will have a score between 71 and 80?

Two thirds of eth students in a class are boys and the rest girls. It is known that eh probability of a girl getting a first class is 0.25 and that of a boy getting a first class is 0.28. find the probability that a student chosen at random will get first class marks in the subject.

Two thirds of the students in a class are boys and the rest girls. It is known that the probability of a girl getting a first class is 0.25 and that of a boy getting a first class is 0.28. find the probability that a student chosen at random will get first class marks in the subject.

The probability that a student will receive A, B, C or D grade or 0.40, 0.3, 0.1 and 0.10 respectively. Find the probability that a student will receive. i. B or C grade ii. at most C grade.

In answering a question on a multiple choice test, a student either knows the answer or guesses. Let 3/5 be the probability that he knows the answer and 2/5 be the probability that he guesses. Assuming that a student who guesses at the answer will be correct with probability 1/3 , what is the probability that the student knows the answer given that he answered it correctly