Taryn mowed 9 lawns in 7.5 hers and received $112.50. Alastair mowed 7 lawns in 5 hrs, and received122.50. How much did Taryn charge to now the lawn, and how much did Alastair charge?? If they both want to earn an additional $735 dollars each, how many additional hours will each spend mowing lawns? Explain.