[" Let "P_(n)" denotes the number of ways in "],[" which three people can be selected out of "],['n'" people sitting in a row,if no two of "],[" them are consecutive.If,"P_(n+1)-P_(n)=15],[" then the value of "'n'" is "]

Let P_(n) denotes the number of ways of selecting 3 people out of 'n' sitting in a row, if no two of them are consecutive and Q_(n) is the corresponding figure when they are in a circle. If P_(n) – Q_(n) = 6, then 'n' is equal to

Number of ways in which three numbers in A.P. can be selected from 1,2,3,..., n is

If ^(2n+1)P_(n-1):^(2n-1)P_(n)=3:5, then find the value of n.

Let P_n denotes the number of ways of selecting 3 people out of n sitting in a row, if no two of them are consecutive and Q_n is the corresponding figure when they are in a circle. If P_n- Q_n= 6, then 'n' is equal to 7 (B) 8 (C) 9 (D) 10

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

prove that total number of ways of selection of r points out of n points in a row such that no two of them are consecutive C(n-r+1,r)

Let P(n) denotes the statement '3^n gt 2^n' . Is P(1) true?

If m>n , the number of ways m men and n women can be seated in a row, so that no two women sit together is

IF ""^(n+5)P_(n-1) = (11 (n-1))/(2)""^(n+3)P_n then the value of n is