Question

One lap of running track measures 255 m. To run 10.0 km, how many laps should you run?

Answer 1

Hint: We are given a running track on which 255 meters make 1 lap. And, we have to find the number of laps that we have to run to cover 10.0 km. So, we will first convert 10.0 kilometers into meters by using the relation between the two. Now, we know the relation between the meter and a lap, so we will find the number of laps in 1 meter then we will simply multiply the number of laps in 1 meter by the meter in 10 kilometers. This way we will get the correct answer.

Complete step-by-step solution:
We are given that 255 meters = 1 lap
So, 1 meter $ = \dfrac{1}{{255}}laps$
Now, we know that –
\[
  \Rightarrow 1km = 1000m \\
   \Rightarrow 10km = 10000m \\
 \]
So, 10000m $ = 10000 \times \dfrac{1}{{255}} = \dfrac{{10000}}{{255}} = 39.22laps$

Hence, to run 10.0. km we should run 39.22 laps.

Note: We use different units to measure different quantities. A specific amount of that quantity is taken as a unit quantity and all the other measurements are done with respect to that quantity. We can also measure one quantity by using various units. Kilometers and meters are the two units used for measuring the distance. One unit can be converted to the other by some formula, 1 kilometer is equal to 1000 meters so we can convert any number of kilometers into meters by using the formula, $x\,km = x \times 1000 = 1000x\,m$ . This way we get $10\,km = 10000\,m$ .