Identify the Given Values

We are given the forward speed $s_1 = 60\text{ km/h}$ and the return speed $s_2 = 40\text{ km/h}$ for an equal distance of $300\text{ km}$ each way.

$s_1 = 60, \quad s_2 = 40$

Apply the Average Speed Formula

For equal distances covered at two different speeds, the average speed is given by the formula for the harmonic mean of speeds.

$\text{Average} \, \text{Speed} = \frac{2 \times s_1 \times s_2}{s_1 + s_2}$

Substitute the Values

Substitute $s_1 = 60$ and $s_2 = 40$ into the formula to compute the numerator and denominator.

$\text{Average} \, \text{Speed} = \frac{2 \times 60 \times 40}{60 + 40} = \frac{4800}{100}$

Calculate the Final Result

Dividing $4800$ by $100$ gives the final average speed of the entire journey.

$\text{Average} \, \text{Speed} = 48\text{ km/h}$