- A0.6 km/h
- B0 km/h
- C1.5 km/h
- D3 km/h
Step-by-Step Solution
True average over equal distances = km/h. Simple mean = 15 km/h. Overstatement = 0.6 km/h.
Answer: A) 0.6 km/h
For an out-and-back trip, a student takes the simple mean of a boat's downstream speed (18 km/h) and upstream speed (12 km/h) as the average speed. By how much does this overstate the true average speed?
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