19. A tank contains 100 gal of fresh water. A solution containing 2 1b/gal of soluble lawn fertilzer runs into the tank at the rate of 1 gal/min, and the mixture is pumped out of the tank at the rate of 2 gal/min Find the maximum amount of fertilizer in the tank and the time required to reach the maximum. A) 50 pounds, 50 minutes B) 48 pounds, 60 minutes C) 60 pounds, 40 minutes D) 48 pounds, 40 minutes 20. In the previous problem, how much salt will there be in the tank after a long period of time? Select the correct answer. a. 1000 kilograms d. 80 kilograms b. 300 kilograms e. none of the above c. 120 kilograms 21. The amount of salt in the tank at time t in the previous two problems is Select the correct answer. a. A(2) = -200+200.3e/40 C. A(t ) = -80+80.30/25 b. A(t ) = 200+ 100e-1/40 d. A(t) = 80-79.7e-1/40 22. The coroner arrives at the scene of a murder at 11 p.m. She takes the temperature of the body and finds it to be 84.20. She waits 1 hour, takes the temperature again, and finds it to be 82.6. She notes that the room tempera- ture is 69. When was the murder committed? (Use 98.6 as Average Body Temp.) A) Approximately 4 p.m. B) Approximately 5 p.m. C) Approximately 7 p.m. D) Approximately 6 p.m