Question

Kusum always forgets how to convert miles to kilometers and back again. However she remembers that her car’s speedometer shows both miles and kilometers. She knows that travelling $50$ miles per hour is the same as travelling $80$ kilometers per hour. To cover a distance of $200\,km$, how many miles would Kusum have to go?

Answer 1

Hint: Here, in the given question, we are given that Kusum always forgets how to convert miles to kilometers and back again. However she remembers that her car’s speedometer shows both miles and kilometers. She knows that travelling $50$ miles per hour is the same as travelling $80$ kilometers per hour. Here, we need to find how many miles she would have to go to cover a distance of $200km$. First, we will find how many miles can be covered in $1km$. After this, we will multiply the total number of miles covered in $1km$ by $200$ to get our required answer.

Complete step by step answer:
We are given that, $50$ miles per hour is the same as travelling $80$ kilometers per hour.So, we can write it as,
$ \Rightarrow 50\,miles/hour = 80\,km/hour$
$ \Rightarrow 80\,km/hour = 50\,miles/hour$
From here, we get
$1\,km = \dfrac{{50}}{{80}}\,miles$
To cover a distance of $200\,km$ = $\dfrac{5}{8} \times 200\,miles$
On simplification, we get $125\,miles$.

Hence, $125$ miles Kusum has to go to cover a distance of $200\,km$.

Note: In order to solve these types of problems read the question carefully and find the value of one term in the form of another as required in the question. Like here we calculated a value of $1\,km$ in terms of miles as we had to find the distance in miles.Remember to write units. We should take care of the calculations so as to be sure of our final answer.