Value of r for which expression `20C_r^20 C_0+20C_(r-2)^20C_1+20C_(r-2)^20 C_2+.........+20C_0^20 C_r` is maximum is equal to (A) 10 (B) 20 (C) 15 (D) 11

Value of r for which expression 20C_(r)^(20)C_(0)+20C_(r-2)^(20)C_(1)+20C_(r-2)^(20)C_(2)+.......+20C_(0)^(20)C_(r) is maximum is equal to (A) 10 (B) 20 (C) 15 (D) 11

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

the value of r for which .^(30)C_r.^(20)C_0+^(30)C_(r-1).^(20)C_1.....+^(30)C_0.^(20)C_r is maximum (A) 10 (B) 15 (C) 20 (D) 25

if 20C_(r-1)=20C_(r+1) then rC_(5)

The sum of the series S=20C_(0)-20C_(1)+20C_(2)-20C_(3)+...+20C_(10) is

The sum of the series 20C_(0)-20C_(1)+20C_(2)-20C_(3)+...+20C_(10) is

If m, n, r, in N then .^(m)C_(0).^(n)C_(r) + .^(m)C_(1).^(n)C_(r-1)+"…….."+.^(m)C_(r).^(n)C_(0) = coefficient of x^(r) in (1+x)^(m)(1+x)^(n) = coefficient of x^(f) in (1+x)^(m+n) The value of r(0 le r le 30) for which S = .^(20)C_(r).^(10)C_(0) + .^(20)C_(r-1).^(10)C_(1) + ........ + .^(20)C_(0).^(10)C_(r) is minimum can not be

If m, n, r, in N then .^(m)C_(0).^(n)C_(r) + .^(m)C_(1).^(n)C_(r-1)+"…….."+.^(m)C_(r).^(n)C_(0) = coefficient of x^(r) in (1+x)^(m)(1+x)^(n) = coefficient of x^(f) in (1+x)^(m+n) The value of r for which S = .^(20)C_(r.).^(10)C_(0)+.^(20)C_(r-1).^(10)C_(1)+"........".^(20)C_(0).^(10)C_(r) is maximum can not be

The sum of the series 20C_(0)-^(20)C_(1)+^(20)C_(2)-^(20)C_(3)+...-...+^(20)C_(10) is:

1.^(20)C_(1)-2.^(20)C_(2)+3.^(20)C_(3)-...-20.^(20)C_(20)