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
Choose the most appropriate option.
A) 35.55 km/hr
B) 36 km/hr
C) 71.11 km/hr
D) 71 km/hr
E) None of these
Explanation:   Total time taken = (160/64 + 160/8)hrs   = 9/2 hrs.   Average speed = (320 × 2/9) km.hr   = 71.11 km/hr.   Answer: 71.11 km/hr
<result>C</result>
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