The value of `sum_(r=0)^(10)(r)^(20)C_r` is equal to: a. `20(2^(18)+^(19)C_(10))` b. `10(2^(18)+^(19)C_(10))` c. `20(2^(18)+^(19)C_(11))` d. `10(2^(18)+^(19)C_(11))`

The value of sum_(r=0)^(20)r(20-r) (.^(20) C_r)^2 is equal to a. 400^(39)C_(20) b. 400^(40)C_(19) c. 400^(39)C_(19) d. 400^(38)C_(20)

Find the sum sum_(k=0)^(10)^(20)C_kdot

The value of sum_(r=0)^(10) (-1)^(r).4^(10-r)""^(30)C_(r)""^(30-r)C_(10-r) is equal to

The value of sum_(r=1)^(15)(r2^r)/((r+2)!) is ((17)!-2^16)/((17)!) b. ((18)!-2^(17))/((18)!) c. ((16)!-2^(15))/((16)!) d. ((15)!-2^(14))/((15)!)

The value of (.^(21)C_(1) - .^(10)C_(1)) + (.^(21)C_(2) - .^(10)C_(2)) + (.^(21)C_(3) - .^(10)C_(3)) + (.^(21)C_(4) - .^(10)C_(4)) + … + (.^(21)C_(10) - .^(10)C_(10)) is

The value of underset(r=0)overset(10)sumr^(10)C_(r),3^(r).(-2)^(10-r) is -

The sum sumsum_(0leilejle10) (""^(10)C_(j))(""^(j)C_(r-1)) is equal to

Find the value of (.^(10)C_(10))+(.^(10)C_(0)+.^(10)C_(1))+(.^(10)C_(0)+.^(10)C_(1)+.^(10)C_(2))+"...."+(.^(10)C_(0)+.^(10)C_(1)+.^(10)C_(2)+"....." + .^(10)C_(9)) .

("lim")_(n->oo)sum_(x=1)^(20)cos^(2n)(x-10) is equal to (a) 0 (b) 1 (c) 19 (d) 20

Find the value of .^(20)C_(0) xx .^(13)C_(10) - .^(20)C_(1) xx .^(12)C_(9) + .^(20)C_(2) xx .^(11)C_(8) - "……" + .^(20)C_(10) .