Number of ways in which a lawn-tennis mixed double be made from seven married couples if no husband and wife play in the same set is a. `240` b. `420` c. `720` d. none of these

Two packs of 52 cards are shuffled together. The number of ways in which a man can be dealt 26 cards so that he does not get two cards of the same suit and same denomination is a. ^52 C_(26). 2^(26) b. ^104 C_(26) c. dot^(52)C_(26) d. none of these

Among 10 persons, A, B, C are to speak at a function. The number of ways in which it can be done if A wants to speak before B and B wants to speak before C is a. 10 !//24 b. 9!//6 c. 10 !//6 d. none of these

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

There are four letters and four directed envelopes. The number of ways in which all the letters can be put in the wrong envelope is a. 8 b. 9 c. 16 d. none of these

The number of four-digit numbers that can be made with the digits 1, 2, 3, 4, and 5 in which at least two digits are identical is a. 4^5-5! b. 505 c. 600 d. none of these

To fill 12 vacancies there are 25 candidates of which 5 are from scheduled caste. If three of the vacancies are reserved for scheduled caste candidates while the rest are open to all; the number of ways in which the selection can be made is a. 5C_3xx^(22)C_9 b. 22 C_9-^5C_3 c. 22 C_3+^5C_3 d. none of these

A team of four students is to be selected from a total of 12 students. The total number of ways in which the team can be selected such that two particular students refuse to be together and other two particular students wish to be together only is equal to a. 220 b. 182 c. 226 d. none of these

The number of ways in which we can select four numbers from 1 to 30 so as to exclude every selection of four consecutive numbers is a. 27378 b. 27405 c. 27399 d. none of these

Rajdhani Express going from Bombay to Delhi stops at five intermediate stations, 10 passengers enter the train during the journey with 10 different ticket of two class. The number of different sets of tickets they may have is a. ^15 C_(10) b. ^20 C_(10) c. ^30 C_(10) d. none of these

A teacher takes three children from her class to a zoo at a time, but she does not take the same three children to the zoo more than once. She finds that she went to the zoo 84 times more than a particular child has gone to the zoo. The number of children n her class is a. 12 b. 10 c. 60 d. none of these