Eight questions are given , each question has an alternative Prove that the number of ways in which a student can select one or more Questions is `(2^(8)-1)`.

There are two bags each of which contains n balls. A man has to select an equal number of balls from both the bags. Prove that the number of ways in which a man can choose at least one ball from each bag is^(2n)C_n-1.

Given that n is the odd the number of ways in which three numbers in A.P. can be selected from {1,2,3,4….,n} is

There are p copies each of n different books. Find the number of ways in which a nonempty selection can be made from them.

A multiple choice emamination has 5 questions. Each question has three alternative answers of which exactly one is correct. The probability that a student will get 4 or more correct answers just guessing is

A candidate is required to answer 6 out of 10 questions, which are divide into two groups, each containing 5 questions. He is not permitted to attempt more than 4 questions from either group. The number of different ways in which the candidate can choose 6 questions is a. 50 b. 150 c. 200 d. 250

In an entrance test, there are multiple choice questions. There are four possible answers to each question, of which one is correct. The probability that a student knows the answer to a question is 90%. If the gets the correct answer to a question, then find the probability that he was guessing.

Find the number of ways in which one or more letters can be selected from the letters PPPQQQQRRRRRSTUV.

A question paper contains 12 questions , divided into three parts . Part A contains 6 questions parts B and C contain 3 questions each A candidate is required to attempt 6 questions , selecting at least 3 questions from part A and at least one from each of the parts B and C In how many ways can the candidate select his 6 questions ?

A person is permitted to selected at least one and at most n coins from a collection of (2n+1) distinct coins. If the total number of ways in which he can select coins is 255, find the value of ndot