Let the number of machines required be x.
The number of machines and the number of days are inversely proportional.
Therefore, from inverse proportionality property:-
60/80 = x/2
60×2 = 80x
x = 60×2/80
x = 120 / 80
x = (3/2) hours.
Therefore, time taken to reach destination, when car is traveling at Speed of 80 Km/h is (3/2) hours.