An executive drove from his home at an average speed of 35 mph to an airport where a helicopter was waiting. The executive then boarded the helicopter and flew to the corporate offices at an average speed of 78 mph. The entire distance from his home to the office was 169.5 miles. If the executive spent the same amount of time in the car as he did the helicopter, how long did it take the executive to get to work?
time = distance/rate
x/35 = (169.5-x)/ 78 x is the distance by car
78x = 35(169.5-x)
78x = 5932.5 - 35x
x = 52.5 m by car time by car = 52.5m / 35 m/hr = 1.5 hr + 1.5 hr by 'copter = 3 hrs