A graphing calculator is recommended.

A20-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 timet is given by

Q(t) =6(1e^0.02t)

wheret is measured in minutes andQ(t) is measured in pounds.

a. How much salt is in the barrel after3min? (Round your answer to two decimal places.)

___lb

(b) How much salt is in the barrel after6min? (Round your answer to two decimal places.)

___lb