" 4.Set of value of "r" for which "^(18)C_(r-2)+2*^(18)C_(r-1)+^(18)C_(r)>=^(20)C_(13)" contains: "

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 in set of values of r for which ^(^^)23C_(r)+2.^(23)C_(r+1)+^(23)C_(r+2)>=^(25)C_(15) 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 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

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

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

If ""^(18)C_(r)=""^(18)C_(r+2) then ""^(R )C_(5) =