A man on tour travels first 160 km at 64 km/hr. and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is:
35.55 km/hr.
36 km/hr.
71.11 km/hr.
71 km/hr.
Explanation:
Total time taken = (160/64 + 160/80) hrs. = 9/2 hrs.
$\therefore$ Average speed = (320 x 2/9) km/hr. = 71.11 km/hr.