The sunscreen company , sells and installs window film for automobiles. Sara manages one shop. She reports that during the past week, her shop applied window film to 19 autos. It charges $ 179.99 for a four door sedan and $149.99 for a two door coupe. Sara reports that $ 3,209.81 in total receipts had been collected. In that week, how many( a) four door sedans and ( b) two door coupes had been serviced? *