Question

Akbar Travels a distance of 120 km with a speed of 40 km per hour and returns with a speed of 30 km per hour calculate the average speed of the entire journey

Answer 1

Here, speed a and b are 30 and 40 respectively.
Now by using the formula,
                average speed = 2ab / a + b, we get
                                         = 2(30)(40) / 70
                                         =  2400 / 70
                                         = 34.28 km/hr