Help.. a hint or solution to this problem..?

I think some units conversions are in order here. Put all those funky imperial units into something your familiar with. Also, calculate the m in the tank (uming 100% ethanol, ignore the gogliox for now). My suspicion is that our intrepid operator has fallen in the tank and is even now displacing valuable reactor space, resulting in the drop in conversion from 80% to 75%. Look at the loss of m from the tank by our operator displacement and see if that doesn't equate to the requisite drop in conversion. Hope that helped.