Question

A scooter can run $225{\text{km}}$ with $5$litre of petrol. How many litres is needed to travel $135{\text{km}}$?

Answer 1

Hint: As we know that a five litre of petrol scooter can travel $225{\text{km}}$. So for one ${\text{km}}$ petrol required will be $\dfrac{5}{{225}}{\text{ litre}}$. Now for $135{\text{km}}$ we just need to multiply it by $135$ and we will get our answer.

Complete step by step solution:
Here we are given the question that a scooter can run $225{\text{km}}$ with $5$litre of petrol. Now we need to find out the petrol when the same scooter travels $135{\text{km}}$
Since we know that for $225{\text{km}}$, $5{\text{litre}}$ of petrol is required. So it is obvious that for $135{\text{km}}$ it would require less than $5{\text{ litre}}$ of petrol. So it is clear that our answer will be less than $5{\text{ litre}}$.

So in this question, we need to find how much petrol is required for travelling $1{\text{km}}$ by that scooter.
We are given in the question that scooter can run $225{\text{km}}$ with $5$ litre of petrol
Now for going $1{\text{km}}$, the amount of petrol required is $\dfrac{5}{{225}}{\text{ litre}}$
This means that $\dfrac{5}{{225}}{\text{ litre}}$ petrol is required for covering $1{\text{km}}$
Now we need to calculate for $135{\text{km}}$

So amount of petrol or the litre of petrol needed to travel $135{\text{km}}$ is equal to $ = \dfrac{5}{{225}}{\text{(135) litre}} = 3{\text{ litres}}$

Therefore the scooter requires $3$ litres of petrol for covering the distance of $135{\text{km}}$

Note: We can do it like this by assuming that it requires $x{\text{ litre}}$ for covering $135{\text{km}}$
$225{\text{km}}$ travelled by $5$ litres
By one litre it travels $\dfrac{{225}}{5} = 45{\text{ litre}}$
By $x$it travels $45x{\text{ litre}}$
We know that $45x = 135$
$x = 3$