On day 1, a car covers 300 km at 50 km/h. On day 2, same car travels at 60 km/h for 5 hours and on day 3, it covers 600 km in 9 hours at constant speed. What is the average speed of this car in these 3 days?
(A) 53 km/h
(B) 55 km/h
(C) 60 km/h
(D) 65 km/h
(E) None of the above
Distance covered on day 1 = 300 km
Distance covered on day 2 = speed
time = 60
5 = 300 km
Distance covered on day 3 = 600 km
Total distance covered = 300+300+600 = 1200 km
Time taken on day 1 to cover 300 km
hours
Time taken on day 2 to cover 300 km = 5 hours
Time taken on day 3 to cover 600 km = 9 hours
Total time taken = 6+5+9 =20 hours
Average speed = (Total distance/total time)
km/h
Hence, the answer is (C).
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