Two brothers leave from the same point driving in opposite directions, the first brother driving at 55 miles per hour and the second at 50 mph. The first brother has a one-hour head starteach brother has a communication device that allows him to talk to the other for up to a 270-mile range, how long will they be able to talk to each other? The communication devices will be out of range __ hours after the first brother left Simplify your answer. Type an integer, fraction or mixed number )