Without stoppages a train travels a certain distance with an average speed of 80 km/h and with stoppages with an average speed speed of 60 km/h. How many minutes per hour does the train stops ?	Choose one:
A) 25 min  B) 10 min  C) 18 min  D) 15 min  E) 20 min
let us assume the distance is x km.   if the train travels 80km/h without stopages then it takes (x/80) hour to rech.   and with stopage it takes (x/60) hour.   let the train stops t min per hour.   then according to the question   (x/80)=(x/60)+(t/60)*(x/60)   then t=15 min.   ANSWER:15 min
<result>D</result>
Without stoppages a train travels a certain distance with an average speed of 80 km/h and with stoppages with an average speed speed of 60 km/h. How many minutes per hour does the train stops ?