Answer:

Explanation:
let x=11.510510510...
multiply by 1000
1000x=11510.510510...
again multiply by 1000
1000,000 x=11510510.510510...
subtract 
999,000 x=1,1 49 9,000
x=11,499,000/999000=3,833,000/333,000=3833/333
333 ) 3833 (11
 -333
 --------
 503
 - 333
 -------
 170
 ------
