The number of values in set of values of `r` for which `^23 C_r+2.^(23)C_(r+1)+^(23)C_(r+2)geq^(25)C_(15)` is

Set of values of r for which, .^(18)C_(r-2)+2.^(18)C_(r-1)+ ^(18)C_(r) ge .^(20)C_(13) contains

Number of elements in set of value of r for which,18C_(r-2)+2*18C_(r-1)+18C_(r)>=20C_(13) satisfied

Element in set of values of r for which,18C_(r-2)+2.18C_(r-1)+18C_(r)>=20C_(13) is :

The number of values of 'r' satisfying the equation ""^(39)C_(3r-1)- ""^(39)C_(r^(2) )= ""^(39)C_(r^(2)-1) - ""^(39)C_(3r) is

The number of values of r satisfying the equation ""^(39)C_(3r-1) -""^(39)C_(r^2) = ""^(39)C_(r^2-1) -""^(39)C_(3r) is

Set of value of r for which C(18,r-2)+2 C(18, r-1)+C(18,r)>=C(20,13) contains

The value of r for which .^(20)C_(r ), .^(20)C_(r - 1) .^(20)C_(1) + .^(20)C_(2) + …… + .^(20)C_(0) .^(20)C_(r ) is maximum, is