Question

A car uses 30 litres of petrol to cover a distance of 375km. How many litres will be needed to cover a distance of 1200km?

Answer 1

Hint: We have been given some quantity of litres of petrol required to cover 375km. We can find the amount of petrol required to cover 1km by dividing it with the distance, 375km. then we can find the amount of petrol required to cover 1200km by multiplying the amount of petrol needed to cover 1km with 1200.

Complete step by step answer:

Let us assume the amount of petrol to cover 1km be x.
The car needs 30 litres of petrol to cover 375km. In terms of x, we can write it as
$ \Rightarrow 375x = 30$
The amount of petrol required to cover 1km is given by,
$ \Rightarrow x = \dfrac{{30}}{{375}}$
After doing the division, we get
$ \Rightarrow x = 0.08$
To find the amount of petrol required to cover 1200km, we must multiply the amount of petrol required to cover 1km with 1200.
Let y be the amount of petrol required to cover 1200km.
$ \Rightarrow y = 1200 \times 0.08$
After doing multiplication, we get,
$ \Rightarrow y = 96$
Therefore the car needs 96 litres of petrol to cover 1200km.

Note: Alternate solution to this problem is given by,
Let x be the amount of petrol required to cover 1200km.
We are given that the car uses 30 litres of petrol to cover a distance of 375km.
So using the concept of proportionality, we can write,
$\dfrac{x}{{1200}} = \dfrac{{30}}{{375}}$
On cross multiplying, we get,
$375x = 30 \times 1200$
On simplification, we get,
$ \Rightarrow x = \dfrac{{30 \times 1200}}{{375}}$
After doing the calculation, we get,
$ \Rightarrow x = 96$
Therefore the car need 96 litres of petrol to cover 1200km.