Robin used 1/4 of a pound of butter to make a cake. before she started, she had 7/8 of a pound of butter. how much butter did robin have when she was done baking? give your answers as a fraction of a pound.

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?