• # question_answer On a journey across Kolkata, a taxi averages 50 km per hour for 50% of the distance. 40 km per hour for 40% of it and 20 km per hour for the remaining. The average speed in km/hour, for the whole journey is: A)  42                    B)  40 C)  35                    D)  45

[b] Total distance = 100 km. Total time$=\frac{50}{50}+\frac{40}{40}+\frac{10}{20}=1+1+\frac{1}{2}=\frac{5}{2}\,\,hour$ Average speed$=\frac{200\times 2}{5}=40\,\,kmph$