Two buses are moving towards each other with speed of 20 km/hr and 34 km/hr respectively. What will be the distance (in metres) between the two buses one second before they collide?
Keerthana takes 9 hrs 20 min in walking a distance and riding back to same place where she started. She could walk both ways in 11 hrs 15 min. The time taken by her to ride back both ways is