Columbus started his journey from Lucknow to Kolkata, Which is 200 K.M., at the speed of 40 KM/hr, then he went to Banglore which is 300 Km, at the speed of 20 KM/hr . Further he went to Ahmedabad which is 500 Km, at the speed of 10 Km/hr. The average speed of Columbus is :
Correct Answer: 14 2/7 KM/hr
Explanation:
Total distance = (200 + 300 + 500) = 1000
Total time = 200/40 + 300/20 + 500/10 = 5 + 15 + 50 = 70 hr Average speed = Total distance / Total time =1000 / 70 = 14.2857 Km/hr.
