# What was his average speed for the entire 6 km?

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A racing driver drove around a 6 km track at 140 km/hr for 3 km, 168 km/hr for 1.5 km and 210 km/hr for 1.5 km.
What was his average speed for the entire 6 km?

posted Sep 27

Total time = 3/140+1.5/168+1.5/210=0.0375 hr
Average speed = 6km/0.0375hr=160 km/hr

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