The balance tank in our milk processing plant in our building holds about 10 gallons of milk. The inlet pipe is 1.5 inches in diameter abd the outlet is 3/4 inches diameter. If milk flows into the tank at .5 ft/sec how fast must it depart to keep from overflowing?

Use the mass continuity equation...

Area1*velocity1=Area2*velocity2

I will be happy to critique your work.