Question

a motorcyclist drives from place A to B with a uniform speed of 30km/hr and returns From place B to A with a uniform speed of 20km/hr. find his average speed.

Answer 1

hey dear here is your answer
1st case:-
given,v=30 km /h
s= x
t1=?

v=s/t1
t1=s/v
t1=x/30 h

2nd case:-
given,v =20 km/h
s=x
t2=?

v=s/t2
t2=s/v
t2=x/20 h

now average speed = total distance / total time taken
=x+x/x/30+x/20
=2x/2x+3x/60
=2x/5x × 60
=24 m/s

hope it helps you. ..