Question 76

A person goes from town A to town B with a speed of 60 km/h and return to A with a speed of 40 km/h. His average speed for the whole journey is

Solution

Average speed is the harmonic mean of both speeds = $$2\div(\frac{1}{60}+\frac{1}{40})$$

= $$2\div(\frac{2+3}{120})$$

= $$2\times\frac{120}{5}=48$$ km/hr

=> Ans - (B)


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