Question 6 [7] The acceptable level of a chemical (called perfluorooctanoic acid or PFOA) in drinking water is 0. 1 micrograms per liter. The function Q = 1: 2e-15 represents the drinking water level of PFOA as a function of t. the number of years since 2009. Given that [ 1. 2e-0.15 di = -8e-0.15; + C and 4 (1, 2e-0.151) = -0. 180-0.157 6.1 After how many years will the drinking level reach the acceptable level? 6.2 At what rate is the drinking water level decreasing in 2013