physics
posted by anil .
A non stop bus goes from one station to another at a speed of 54 km/h. The bus returns from the second station to first station at a speed of 36 km/h. Find the average speed of the bus.

figure the time it took going, and coming.
t=d/v where d is the distance each way.
then
add the times
avgvelocity=2d/total time