A graphing calculator is recommended, A 60-gallon barrel is filled completely with pure water. Salt water with a concentration of 0.3 lb/gal is then pumped into the barrel, and the resulting mixture overflows at the same rate. The amount of salt in the barrel at time t is given by Olt) = 18(1 - e-0.08) where t is measured in minutes and o(t) is measured in pounds. (a) How much salt is in the barrel after 5 min? (Round your answer to two decimal places.) | Iь (b) How much salt is in the barrel after 10 min? (Round your answer to two decimal places.) | ГБ lb (c) Draw a graph of the function Oſt). Qt) Qit) 20 20 15 15 10 10 5 20 t 100 40 80 60 ht 100 O 20 40 60 80 Oxt) Oxt) 20 20 15 15 10 10 5 t Lt O 20 40 60 80 100 O 20 40 60 80 100 (d) Use the graph in part (c) to determine the value that the amount of salt in the barrel approaches as t becomes large. | | lb