A car travels first 160 km at 75 km/hr and the next 160 km at 70 km/hr. What is the average speed for the first 320 km of the tour? Pick one.
A) 71.11 B) 71.12 C) 72.4 D) 71.17 E) 71.13
72.4ar travels first 160 km at 75 km/hr   Time taken to travel first 160 km = distancespeed=160/75   72.4ar travels next160 km at 70 km/hr   Time taken to travel next 160 km = distancespeed=160/70   Total distance traveled = 160+160=2×160   Total time taken = 160/75+160/70   Average speed = Total distance traveled/Total time taken=320/(160/75+160/70)=72.4 km/hr   Answer:72.4
<result>C</result>
A car travels first 160 km at 75 km/hr and the next 160 km at 70 km/hr. What is the average speed for the first 320 km of the tour?