A car covers 150 km in 3 hours. How much distance would the car cover in 12 minutes?

Hint: Distance car covers in 3 hours is given, but the distance required is to be calculated in minutes so we have to carry out conversion and convert hours into minutes to get the required value of distance using the unitary method.
In unitary method:
If a = x, then b in terms of x:
 $ b = \dfrac{x}{a} \times b $

Complete step-by-step answer:
Distance covered in 3 hours is 150 km, then in 1 hour it covers:
3 hours = 150 km
1 hour = $ \left( {\dfrac{{150}}{3} \times 1} \right)km $
1 hour = 50 km
Thus, the distance travelled in 1 hour is 50 km
As we have to calculate the distance for the time in minutes, we have to convert hours into minutes.
1 hour = 60 mins, this means that the distance travelled in 1 hour is the distance travelled in 60 mins.
So, the distance covered in 60 minutes is 50 km
Now, the distance covered in 12 minutes can be calculated by the unitary method.
60 minutes = 50 km
$\Rightarrow$ 12 minutes = $ \left( {\dfrac{{50}}{{60}} \times 12} \right)km $
$\Rightarrow$ 12 minutes = 10 km
Therefore, the distance the car would cover in 12 minutes is 10 km.

Note: Carry out conversions wherever necessary to get the answer in the asked units. We use a unitary method to find the value of a single unit when that multiple is given,in the unitary method we always keep the known values on the left and the values to be calculated on the right side of the equation.