Answer:
Explanation:
Let x m/h be the speed of first bus.
Then speed of second bus=x-13 m/h
fist covers covers distance=3x
second covers the distance=3(x-13)=3x-39
again 3x+(3x-39)=339
6x=339+39=378
x=378/6=63
so speed of first bus=63 m/h
speed of second bus=63-13=50 m/h