Question

sum of series (1/1*2)+(1/2*3)+(1/3*4)+....(1/n*(n+1)

Answer 1

you have to find summation (1/n(n+1) )

note that 1/n(n+1) = [ (n+1) - n ]/[ n(n+1) ]
does this help your case?

Answer 2

Does we solve it for n terms first??

Answer 3

just simplify [ (n+1) - n ]/[ n(n+1) ] first.