A woman wantes to drive 83 km in 2 h. If she average 42 km/h for the first 1.27 h, what average velocity must she maintain for the remaining time in km/h
42 * 1.27 = 53.34 in first hour
so 83 - 53.34 = 29.66 km in second hour
she has 2 - 1.27 = .73 hours left
so she must do
29.66 km / .73 hr = 40.63 km/hr