Amixture consisting of 30 ml of waste and 270 ml of seeded dilution waster has an initial do of 8.55 mg/l; after five days, it has a final do of 2.40 mg/l. another bottle containing just the seeded dilution water has an initial do of 8.75 mg/l and a final do of 8.53 mg/l. find the five-day bod of the waste.