The distance between A and B is 2304 km. A train covers a journey between A to B at the uniform speed of 60 km/h and retuns from B to A at the uniform speed of 40 km/h .What is the average speed of the train during the whole journey?
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54 km/h
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48 km/h
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50 km/h
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56 km/h
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None of these
B
Correct answer
Explanation
Average speed for a round trip is total distance divided by total time, not the average of the two speeds. Total distance = 4608 km (2304 × 2). Time going = 2304/60 = 38.4 hours; time returning = 2304/40 = 57.6 hours. Average speed = 4608/96 = 48 km/h. Option B (48 km/h) is correct.