Question

A Car Covers First half of distance between 2 Stations At A Speed Of 40kmph And The Remaining Half At A Speed of 60 Kmph Calculate the Average

Answer 1

total distance covered (S) = 120km/h
first 30km is covered at 30km/h
time taken is (T) 30/30 = 1
let the train cover next 90 km at speed of x km/h
then time taken (T2) = 90 km/x hr
average speed = total distance/total time
                    60 = 120/ (t1 + t2)
                    60 = 120/ (t1 + 90/x)
           1 + 90/x = 2
                 90/x = 1
therefore       x = 90 km/h