A person covers a certain distance by bus at 45 km/h and immediately returns to the starting point by car at a speed of 80 km/h. What is his average speed during the whole journey?
Answer & explanation
Correct answer: option 1
Average speed = \(\frac{2 × S1 × S2 }{S1 + S2}\)
= \(\frac{2 × 80 × 45 }{80 +45}\)
= \(\frac{7200 }{125}\)
= 57.6 km/h