Ahmad opened a savings account with $9000 and was paid simple interest at an annual rate of 8%. When Ahmad closed the account he was paid $1440 interest. How long was the account open for in years.

The serenity and the mystic are sail boats. the serenity and the mystic start at the same point and travel away from each other in opposite directions. the serenity travels at 16 mph and the mystic travels at 19 mph. how far apart will they be in 3 hours?