An old single storey, 500m3 home with an air exchange rate of 0.6 ach, uses a gas oven for cooking. This gas range is the only source of CO for the home and ambient outdoor concentrations can be considered negligible. Cooking commenced from 12 noon on Christmas day using both the oven and four burners for four straight hours. Assuming that the air is well mixed, estimate the concentration in the home at 2pm,4pm and again at 8pm ? [15 marks] Explain how these answers would change citing a relevant model equation if the ventilation rate were 0.3 ach. [5 marks] For the scenario outlined within question 2, briefly describe two strategies for reduction of CO exposure within the home. [10 marks]