A car moving with 6/9 of its actual speed covers 50 km in 1 hour 40 min. What is the actual speed of the car?

45 Km/hr

First, convert the time:

• 1 hour 40 minutes = $\frac{5}{3}$ hours

The car is moving at $\frac{6}{9} = \frac{2}{3}$ of its actual speed.

Using the speed formula:

$\text{Speed} = \frac{\text{Distance}}{\text{Time}}$

$\text{Reduced speed} = \frac{50}{5/3} = 50 \times \frac{3}{5} = 30\text{ km/hr}$

Since $30\text{ km/hr}$ is $\frac{2}{3}$ of the actual speed:

$\frac{2}{3} \times \text{Actual speed} = 30$

$\text{Actual speed} = 30 \times \frac{3}{2} = 45\text{ km/hr}$