Question 3705
  Consider the whole as 1.
  The remaining work is 1 - 16/34 = 1 - 8/17 = 9/17.
  Each man can finish 1/(34*25) = 1/ 850 of the whole work in one day.
  
So, the remaining 15 men can finish 15/850 = 3/170 of the whole work in one day.

  Hence, it takes (9/17) / (3/170) = 9*10/3 = 30 more days to finish the rest
  of the work. 

  Kenny