Pls help...

Anjana (ipcc) (46 Points)

02 June 2011  

sum of n terms of the series 0.1+0.11+0.111+...is

1/9{ n-(1 - ( 0.1 ) ⁿ) }

n-1 - (0.1)ⁿ /9

1/9 {n- (1-(0.1) ⁿ} /9

pls solve this....