Question

A car consumes 5 litres of petrol to travel 60 km. What distance can be travelled if the car has only 3 litres of petrol?

Answer 1

Answer:

36 km

Step-by-step explanation:

As per the provided information in the given question, we have :

• A car consumes 5 litres of petrol to travel 60 km.

We are asked to calculate the distance can be travelled if the car has only 3 litres of petrol.

Let us suppose the distance can be travelled if the car has only 3 litres of petrol as x. So, less litres will be consumed by the car to travel less distance.

• Less amount of petrol ➛ Less distance will be covered

Clearly, here it is direct proportion. The construction of table is as follows :

$\boxed {\begin{array}{c|c|c} \underline{\rm{ Amount \: of \: petrol \; (in \; \ell) }} & \underline{\rm{5}} & \underline{\rm{3}} \\ \\ \underline{\rm{Distance \: (in\: km) }} & \underline{\rm{60}} & \underline{\rm{x}}\end{array} }$

Now,

$\longmapsto \rm { \dfrac{5}{60} = \dfrac{3}{x} }$

Cross multiplying the values in order to balance the equation.

$\longmapsto \rm { 5x = 60(3) }$

Performing multiplication.

$\longmapsto \rm { 5x =180 }$

Transposing 5 from L.H.S to R.H.S.

$\longmapsto \rm { x =\cancel{ \dfrac{180}{5}} }$

Dividing 180 by 5.

$\longmapsto \bf { x = 36 }$

∴ 36 km can be travelled if the car has only 3 litres of petrol.

$\rule{200}2$

Note :

$\sf{If \: x \: and \: y \: are \: in \: variation,then} \\ \\ \bull \: \: \: \sf{ \dfrac{x_1}{y_1} = \dfrac{x_2}{y_2} = \dfrac{x_3}{y_3} = \dfrac{x_n}{y_n} }$

Answer 2

Step-by-step explanation:

$\red{\mid{\fbox{\tt{Given:}}\mid}} \:$

‣ A car consumes 5 litres of petrol to travel 60km.

$\red{\mid{\fbox{\tt{To \: Find:}}\mid}} \:$

‣ Distance that can be travelled if the car has only 3 litres of petrol.

$\red{\mid{\fbox{\tt{Understanding:}}\mid}} \:$

❖ To solve this question we can use two methods :

• Unitary Method
• Cross Multiplication

➛ In unitary method we will first find how much distance car covers in one litre of petrol. Then we can find the value of how much distance it covers with 3 litres of petrol.

➛ In cross multiplication we make a table then we put x in the missing values the cross multiply and then solve it further.

Let's start doing ✨

$\huge\sf\blue{Solution :}$

Let's first do with unitary method :

$\implies \displaystyle{ \frac{60}{5} \times 3 = distance }$

$\implies \displaystyle{12 \times 3 = distance}$

$\implies \displaystyle{36 \: km = distance}$

∴ Distance a car can travel if it has 3 litres of petrol is 36 km.

Now, let's do with cross multiplication :

To do this construct a table like this :

$\begin{gathered}\boxed {\begin{array}{c|c|c} \underline{\rm{ Amount \: of \: petrol \; (in \; \ell) }} & \underline{\rm{5}} & \underline{\rm{3}} \\ \\ \underline{\rm{Distance \: (in\: km) }} & \underline{\rm{60}} & \underline{\rm{x}}\end{array} }\end{gathered} \:$

Note:

→ If table is not visible please refer to the attachment.

$\implies \displaystyle{ \frac{5}{60} = \frac{3}{x} }$

$\implies \displaystyle{5x = 3 \times 60}$

$\implies \displaystyle{5x = 180}$

$\implies \displaystyle{x = \frac{180}{5} }$

$\implies \displaystyle{x = 36}$

∴ Distance a car can travel if it has 3 litres of petrol is 36 km.

$\huge\sf\blue{More \:Information :} \:$

➲ Distance is a path travelled by an object in a particular direction.

➲ It's SI unit is km.

➲ It is scalar quantity.

➲ Formula to calculate distance is:

★Distance = Speed X Time