The value of `23C_6+sum_(j=1)^5 28-jC_5+sum_(k=1)^5 33-kC_(28-k)` is

The value of cot (sum_(n=1)^(23) cot^(-1) (1 + sum_(k=1)^(n) 2k)) is

The value of sum_(i=1)^(n) sum_(j=1)^(i) sum_(k=1)^(j) 1 is

The value of sum_(r=1)^(n+1)(sum_(k=1)^(n)C(k,r-1))=

sum_(k=0)^(5)(-1)^(k)2k

The value of sum_(r=1)^(n+1)(sum_(k=1)^n ^kC_(r-1)) (where r, k, n in N ) is equal to

The value of cot(sum_(n=1)^(23)cot^-1(1+sum_(k=1)^n2k)) is

The value of cot(sum_(n=1)^23 cot^-1(1+sum_(k=1)^n 2k)) is (a) 23/25 (b) 25/23 (c) 23/24 (d) 25/26

The value of cot(sum_(n=1)^(2)cot^(-1)(1+sum_(k=1)^(n)2k)) is (a) (23)/(25) (b) (25)/(23) (c) (23)/(24) (d) (25)/(26)