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A) 220 km

B) 218 km

C) 216 km

D) 230 km

Answer

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Then we will use the formula for speed and evaluate the value of distance x.

The speed is given by:-

\[{\text{speed}} = \dfrac{{{\text{distance}}}}{{{\text{time}}}}\]

Let the distance covered by the car be x

Now we are given that:-

Speed of the car is 20 m/s

The time taken by the car is 3 hours.

Since the time is given in hours and speed is given in m/s so we need to make the unit of time the same.

Hence in order to make the unit same, we will convert hours into seconds

Now since we know that:-

\[1hr = 60\min \] and \[1\min = 60\sec \]

Therefore,

\[1hr = 60 \times 60\sec \]

Hence 3hr will be equal to:-

\[3hr = 3 \times 60 \times 60\sec \]

Calculating the value we get:-

\[3hr = 10800\sec \]

Now we know that the speed is given by:-

\[{\text{speed}} = \dfrac{{{\text{distance}}}}{{{\text{time}}}}\]

Hence putting in the respective values we get:-

\[20 = \dfrac{x}{{10800}}\]

Now evaluating for the value of x we get:-

\[

x = 20 \times 10800 \\

\Rightarrow x = 216000m \\

\]

Therefore, the distance covered is 216000 m

Now we will convert this distance into kilometers.

We know that:

\[

1km = 1000m \\

\Rightarrow 1 m = \dfrac{1}{{1000}}km \\

\]

Hence 216000m will be equal to:-

\[216000m = \dfrac{{216000}}{{1000}}km\]

Calculating the value we get:-

\[216000m = 216km\]

Hence the distance covered by the car is 216 km

\[1m/\sec = \dfrac{{18}}{5}km/hr\]