a 90-gallon tank is filled with brine (water nearly saturated with salt; used as a preservative) holding 14 pounds of salt in solution. a salt solution containing 0.5 pounds of salt per gallon is added to the tank at the rate of 3gal/min. the contents of the tank are continuously and thoroughly mixed and drained out at thirteen quarts per minute. what is the amount of salt in the tank after an hour? round your answer to three decimal places if necessary.
