[" The total no.of neutrons present in "54mLH_(2)C],[" are: "],[" 1."3N_(A)],[" 2."30N_(A)],[" 3."24N_(A)],[" 4.none of these "]

Calculate the total ions & charge present in 4.2 gm of N^(-3)

The total number of ways in which 2n persons can be divided into n couples is a. (2n !)/(n ! n !) b. (2n !)/((2!)^3) c. (2n !)/(n !(2!)^n) d. none of these

The total number of ways in which 2n persons can be divided into n couples is a. (2n !)/(n ! n !) b. (2n !)/((2!)^3) c. (2n !)/(n !(2!)^n) d. none of these

The total number of ways in which 2n persons can be divided into n couples is a. (2n !)/(n ! n !) b. (2n !)/((2!)^3) c. (2n !)/(n !(2!)^n) d. none of these

The total number of ways in which 2n persons can be divided into n couples is a. (2n !)/(n ! n !) b. (2n !)/((2!)^3) c. (2n !)/(n !(2!)^n) d. none of these

The total number of ways in which 2n persons can be divided into n couples is a. (2n !)/(n ! n !) b. (2n !)/((2!)^3) c. (2n !)/(n !(2!)^n) d. none of these

The solution of the equation sin^3x+sinxcosx+cos^3x=1 is (n∈N) (a) 2npi (b) (4n+1)pi/2 (c) (2n+1)pi (d) None of these

The middle term in the expansion of ((2x)/3-3/(2x^2))^(2n) is a. \ ^(2n)C_n b. (-1)^n\ ^(2n)C_(n\ )x^(-n) c. \ ^(2n)C_n x^(-n) d. none of these

The total number of ways in which 2n persons can be divided into n couples is a.(2n!)/(n!n!) b.(2n!)/((2!)^(3)) C.(2n!)/(n!(2!)^(n)) d.none of these

If A=[(2,-4),(1,-1)] the value of A^n is (A) [(3^n,(-4)^n),(1,(-1)^n)] (B) [(3n,-4n),(n,n)] (C) [(2+n,5-n),(n,-n)] (D) none of these