A person runs at an average speed of 20 km/h for 30 minutes and cycles at a speed of 32 km/h for 1 hour 15 minutes. Calculate the average speed (in km/h, rounded off to 1 decimal place).
Answer & explanation
Correct answer: option 2
Average Speed = \(\frac{Total\; Distance }{Total\; Time }\)
Distance = Speed × Time
Total distance = 20 × \(\frac{30 }{60 }\) + 32 × \(\frac{75 }{60 }\)
= 10 + 40 = 55 km
Total time = \(\frac{30 }{60 }\) + \(\frac{75 }{60 }\) = \(\frac{105 }{60 }
Average speed = \(\frac{50 × 60 }{105 }\) = 28.57
= 28.6 km/h