If `sum_(r=1)^n I(r)=2^n-1` then `sum_(r=1)^n 1/I_r` is

If sum_(r=1)^n I(r)=(3^n -1) , then sum_(r=1)^n 1/(I(r)) is equal to :

If sum_(r=1)^(n) r=210, then : sum_(r=1)^(n) r^(2) =

If sum_(r=1)^n r=55 , F i nd sum_(r=1)^n r^3dot

If sum_(r=1)^(n)cos^(-1)x_(r)=0, then sum_(r=1)^(n)x_(r) equals to

If sum_(r=1)^(n) t_(r ) = sum_(k=1)^(n) sum_(j=1)^(k) sum_(i=1)^(j) 2 , then sum_(r=1)^(n) (1)/( t_(r )) equals :

If sum_(r=1)^(n)Cos^(-1)x_(r)=0," then "sum_(r=1)^(n)x_(r) equals to

sum_(r=1)^(n)r^(3)=f(n) then sum_(r=1)^(n)(2r-1)^(3) is equal to

If I(r)=r(r^2-1) , then sum_(r=2)^n 1/(I(r)) is equal to

Let sum_(r=1)^(n)r^(4)=f(n)," then " sum_(r=1)^(n) (2r-1)^(4) is equal to