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 byQ(t) = 18(1 e- e-0.02t)where t is measured in minutes and Q(t) is measured in pounds.(a) How much salt is in the barrel after 2 min? (Round your answer to two decimal places.)lb(b) How much salt is in the barrel after 4 min? (Round your answer to two decimal places.)lb (c) Draw a graph of the function Q(t).Q(t)2015105Q(t)20151052020404060608080100100ttQ(t)2015105Q(t)20151052020404060608080(d) Use the graph in part (c) to determine the value that the amount of salt in the barrel approaches as t becomes large.lb100100tt

Given Information: Amount of salt in the barrel at time t is Qt=181-e-0.02t. To find: a) Qt at time t=2 min. b) Qt at time t=4 min. c) Graph the given function Qt d) Amount of salt when the time extremely large. a) Substitute t=2 in Qt Qt = 181-e-0.02tQ2 = 181-e-0.022= 181-e-0.04= 181-0.9607894392= 180.03921056085= 0.7057900953≈ 0.71 Thus, the amount of the salt in the barrel is 0.71 lb in 2 minutes.b) Substitute t=4 in Qt Qt = 181-e-0.02tQ4 = 181-e-0.024= 181-e-0.08= 181-0.9231163464= 180.07688365361= 1.383905765≈ 1.38 Thus, the amount of the salt in the barrel is 0.38 lb in 4 minutes.c) Sketch the graph: Step 1: Open the Ti-83 calculator. Click on the key y, then it displays as below: Step 2: Type the function as "18 - (18/e^0.02*x) as per following step. Click as in this order: 1 8 - ( 18 ÷ For e, click the key "2nd" and then Ln key 0 . 0 2 × For x, Click the key "ALPHA" and "STO↦" key. Then click on ) key. Then the calculator displays as follows:Step 3: Set the "WINDOW" as follows by click the WINDOW key. Step 4: Click on "TRACE" key, then the graph is traced as follows. Hence, the correct option for the given graph is (a). d) As per the graph, the amount of salt becomes greater than or equal to 18 lb when the time becomes extremely large.