If a person walks 25% more than of his usual speed, reaches his distance 90 minutes before. If the destination is 420 km away, then the usual speed of a person is (in km/hr)?
Let the usual speed be x km/hr New speed = 125% of x = 5x/4 km/hr Distance = 420 km According to the question 420/x – 420/(5x/4) = 90/60 420 x [(5 – 4)/5x] = 3/2 Therefore, x = 420 x (1/5) x (2/3) = 56 km/hr
