A car, moving at the rate of 60km /hr,does a journey in 15 min. How long would it take , if the speed is reduced to 36km /hr?

Answer 1

60 * 1/4 = 60/4 = 15 km

36 t = 15
t = 15/36 hour
15/36 * 60 = 25 minutes

Answer 2

since the distance is the same, rate*time is constant. So, you want m minutes where

36m = 15*60