Bret leaves school to walk home. His friend, Tallulah, notices 0.4 hours later that Bret forgot his phone at the school. So Tallulah rides her bike to catch up to Bret and give him the phone. If Bret walks at 2.9 mph and Tallulah rides her bike at 9.8 mph, find how long (in hours) she will have to ride her bike until she catches up to him.