Question

Shalini's car has 15 L 315 ml of petrol in its tank, while her scooter has 2 L 945 ml of petrol in its tank. How much petrol is there in both the vehicles altogether?
\[\begin{align}
  & \text{A}.\text{ 18 L 37}0\text{ ml} \\
 & \text{B}.\text{ 18 L 26}0\text{ ml} \\
 & \text{C}.\text{ 13 L 945 ml} \\
 & \text{D}.\text{ 13 L 37}0\text{ ml} \\
\end{align}\]

Answer 1

Hint: To solve this question, we will first convert ml into L by using conversion formula as 1L = 1000ml then after converting both 15 L 315 ml and 2 L 945 ml of petrol into entirely in L we will add both of the values obtained in liters to get the final amount of petrol available.

Complete step-by-step answer:
We are given that Shalini's car has 15 L 315 ml of petrol in its tank.
Let us first convert ml into L.
The formula of conversion of ml into L is given as below:
1 L = 1000 ml
The car's tank has 15 L 315 ml of petrol. Converting 315 ml into l using above stated conversion formula we get:
Using unitary method:
\[\begin{align}
  & 1L=1000ml \\
 & \Rightarrow 1000ml=1L \\
 & \Rightarrow 1ml=\dfrac{1}{1000}L \\
 & \text{then }315ml=\dfrac{315}{1000}L \\
 & \Rightarrow 315ml=0.315L \\
\end{align}\]
Shalini’s car has 15 L + 0.315 L of petrol.
\[\text{Shalini}\text{s car has 15}.\text{315 L of petrol }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. (i)}\]
Now, consider the petrol Shalini's scooter has. It has 2 L 945 ml of petrol in its tank. Again, we will convert 945 ml in L and then add it to given 2 L we get the required L of petrol which Shalini's scooter has:
Using unitary method:
\[\begin{align}
  & 1L=1000ml \\
 & \Rightarrow 1000ml=1L \\
 & \Rightarrow 1ml=\dfrac{1}{1000}L \\
 & \text{ then 945}ml=\dfrac{945}{1000}L \\
 & \Rightarrow 945ml=0.945L \\
\end{align}\]
Therefore, Shalini's scooter has 2 L + 0.945 L of petrol.
\[\text{Shalini}'\text{s scooter has 2}.\text{945 L of petrol }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. }\text{. (ii)}\]
From equation (i) and (ii) we get:
The petrol both the vehicle together has \[\Rightarrow 15.315+2.945L=18.260L\]
Therefore, both the vehicles together have 18.260 L of petrol.
Converting 0.260 L into ml by unitary method, we get:
\[\begin{align}
  & 1ml=\dfrac{1}{1000}L \\
 & \Rightarrow 1000ml=1L \\
 & \Rightarrow 1L=1000ml \\
 & \text{then 0}\text{.260L}=0.260\times 1000ml \\
 & \Rightarrow 0.260L=260ml \\
\end{align}\]
Both the vehicles have then 18 L 260 ml of petrol, option B is correct.

So, the correct answer is “Option B”.

Note: Another way to solve this question can be directly adding l to L and ml to ml.
Both vehicles have; 15 L 315 ml + 2 L 945 ml of petrol.
\[\begin{align}
  & \left( 15+2 \right)L\left( 315+945 \right)ml \\
 & 17L\left( 1260 \right)ml \\
 & \text{and as 1260ml} \\
 & \Rightarrow \text{1L 260ml} \\
\end{align}\]
Both vehicles have (17+1) L (260) ml = 18 L 260ml of petrol.