mohit u have made a mistake i think....here should be neagative power....
let talk about this...
1.111...11(let there is 11 times 1's after decimal point)
...we can write is like this...1*20+.111111(11 times) ....1+(1-2-11) or (2-2-11)....
....example:-
0.11 ....decimal equivalent is....(1-1/4)