`(1- 1/(n+1))+(1-2/(n+1))+(1-3/(n+1))+…….+(1-n/(n+1))` का योग ज्ञात करें।

Options

A. `n`
B. `1/2n`
C. `(n+1)`
D. `1/2(n+1)`

Answer

B

Explanation

`(1-1/(n+1))+(1-2/(n+1))+`
`=(1-3/(n+1))+………….+(1-n(n+1))`
`=n-(1+2+3……….n)/(n+1)`
`=n-(n(n+1))/(2(n+1))`
`{1+2+3………….n=(n(n+1))/2}`
`=n=n/2=n/2`