Use the following information to answer question 11 and 12 A quantity of water contains 700g of pollutants. Each time the water passes through a filter, 18% of the pollutants are removed. This situation can be modelled by the equation . m(n) = 574(0.82)"-1 11. What is the mass of pollutants remaining, to the nearest tenth, after it passes through 6 filters? [2 mark] 12. Using a graphical approach, determine how many filters are needed to reduce the mass of pollutants to less than 80 grams? Please explain/show your strategy. [2 marks] Use the following information to answer question 13 A radioactive substance decays from 16g to 12.5g in 5 years. 13. What is the half-life of this substance? Round your answer to one decimal place. [2 marks]