An extruder can fill an empty bin in 2 hours and a packaging crew can empty a full bin in 5 hours. If a bin is half full when an extruder begins to fill it and a crew begins to empty it how long will it take to fill the bin?

Answer 1

rate to empty bin = bin/5
rate to fill the bin = bin/2

combined rate to fill the bin = bin/2 - bin/5 = 3bin/5

time to fill half a bin = (bin/2)/(3bin/5) = 5/6 hrs. or 50 minutes.

Extruder ????