please when providing solutions to these questions, solve on a sheet of paper

5. Imagine that 300lb of dry sewage is dumped into a small lake, the volume of which is 300 million liters. How many tonnes of oxygen are needed to completely degrade this sewage? You may assume the sewage has an elemental composition of C6H12O6. 6. Assume that an incorrectly adjusted lawn mower is operated in a closed two-car garage such that the combustion reaction in the engine is C8H14+15/2O28CO+7H2O. How many grams of gasoline must be burned to raise the level of CO by 1000ppm ? Assume the garage has a space of 6500ft3. 7. A sewage treatment plant is designed to process 9.3106L of sewage daily. What diameter (in feet) tank is required for the primary setting process if the residence time is to be 7h ? please assume the tank is cylindrical and 2m deep