A man walks from point P to Z at a speed if 35 km/h, but comes back from Z to P at a speed of 45 km/h. Find his average speed ( in km/h ) .
Answer & explanation
Correct answer: option 2
Average speed = \(\frac{2xy}{x + y}\)
= \(\frac{2 × 35 × 45}{80}\) = \(\frac{315}{8}\) km/h