A rabbit runs in a straight line with a velocity of +1.4 m/s for a period of time, rests for 12 s, and then runs again along the same line at +0.64 m/s for an unknown amount of time. The rabbit travels a total distance of 1320 m, and its average speed is 0.84 m/s.
what is the total time rabbit spends running at 1.4 m/s?