Let the speed of the car leaving A to be ‘x’ km/h and the speed of the car leaving B to be ‘y’ km/h.
Total distance=80 km
Also 1 hour 20 mins= 4/3 hour
When an automobile goes in the same direction as a specified condition,
Distance travelled by y= 8y km
Distance travelled by x= 8x= 80+8y
Now, Equation formed is 8x=80+8y
Similarly, For opposite direction,
Distance travelled by x= (4/3)x
Distance travelled by y= (4/3) y
Also total distance covered= 4/3
Solving Equation (1) and (2)
Substituting the value of (3) in (2) we get,
Also we know that, x=10+y=> x= 10+25=> x=35
Thus, Speed of car starting from A is 35km/h
Speed of car starting from B is 25km/h