Kanchan has 10 friends among whom two are married to each other. She wishes to invite five of them for a party. If the married couples refuse to attend separately, then the number of different ways in she can invite five friends is
a. `""^8C_5`
b. `2xx ""^8C_3`

c. `""^10 C_5-2xx ""^8C_4`
d. none of these

Sanjay has 10 friends among whom two are married to each other she wishes to invite 5 of the them for a party if the married couple refuse to attend separately then the number of different ways in which she can invite five friends is

Eight chairs are numbered 1 to 8. Two women and three men wish to occupy one chair each. First, the women choose the chairs from amongst the chairs marked 1 to 4, and then the men select th chairs from amongst the remaining. The number of possible arrangements is a. ""^6C_3 xx ""^4C_2 b. ""^4P_2 xx ""^4P_3 c. ""^4C_2 xx ""^4P_3 d. none of these

If n objects are arrange in a row, then the number of ways of selecting three of these objects so that no two of them are next to each other is a. "^(n-2)C_3 b. "^(n-3)C_2 c. "^(n-3)C_3 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

The third term of a geometric progression is 4. Then the product of the first five terms is a. 4^3 b. 4^5 c. 4^4 d. none of these

In a group of boys, two boys are brothers and six more boys are present in the group. In how many ways can they sit if the brothers are not to sit along with each other? a. 2xx6! b. ^7P_2xx6! c. ^7C_2xx6! d. none of these

An oil drop has 8.01xx10^-19 C charge calculate the number of electrons in this drop.

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 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

Among the 8! [permutations of the digits 1, 2, 3..., 8, consider those arrangements which have the following property. If we take any five consecutive positions the product of the digits in these positions is divisible by 5. The number of such arrangements is equal to a. 7! b. 2.(7!) c. 7C_4 d. none of these