A man has three friends. The number of ways he can invite one friend everyday for dinner on six successive nights so that no friend is invited more than three times is a. `640` b. `320` c. `420` d. `510`

A man has 10 friends. In how many ways he can invite one of more of them to a party ?

A man has 6 friends .how many ways can be invite one or more of them to a party?

A man has 6 friends. In how many ways can he invite one or more of them to a party?

A man has 7 friends . In how many ways may he invite one or more of them to party?

Find the number of ways to give 16 different things to three persons A, B, C so that B gets 1 more than A and C gets 2 more than B.

In an examination of nine papers, a candidate has to pass in more papers than the number of paper in which he fails in order to be successful. The number of ways in which he can be unsuccessful is a. 256 b. 266 c. 193 d. 319

A gentle man wants to invite six friends. In how many ways can he send invitation cards to them, if he has three servants to carry the cards.

The number of ways of choosing a committee of two women and three men from five women and six men, if Mr. A refuses to serve on the committee if Mr. B is a member and Mr. B can only serve if Miss C is the member of the committee is a. 60 b. 84 c. 124 d. none of these

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

A person tries to form as many different parties as he can, out of his 20 friends. Each party should consist of the same number. How many friends should be invited at a time? In how many of these parties would the same friends be found?