A man on tour travels first 160 km at 64 km/he and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is? Pick one:
A) 71.17 km/hr	B) 71.21 km/hr	C) 71.11 km/hr	D) 81.11 km/hr	E) 77.11 km/hr
Total time taken = (160/64 + 160/8) = 9/2 hrs.   Average speed = 320 * 2/9 = 71.11 km/hr.   Answer:71.11 km/hr
<result>C</result>
A man on tour travels first 160 km at 64 km/he and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is?