Question

A scooter requires 2 liters of petrol to cover 80km. How many liters of petrol is required to cover 1 km?

Answer 1

Hint: In this question it is given that a scooter requires 2 liters of petrol to cover 80km. We have to find how many liters of petrol is required to cover 1 km. So to find the solution we have to use the ‘unitary method’ which states that, to solve a problem we have to first find the value of a single unit, and then find the necessary value by multiplying the single unit value.

Complete step-by-step answer:
Given, a scooter requires 2 liters of petrol to cover 80km.
So we can write the above statement as,
To cover 80km, the scoter required = 2 liter petrol
$\therefore$ To cover 1 km , the scooter required = ${\displaystyle \frac{2}{80}}$ liter petrol
So we have to divide 2 by 80,
$${\displaystyle \frac{2}{80}}$$
$$={\displaystyle \frac{2\times 10}{80\times 10}}$$
$$={\displaystyle \frac{20}{800}}$$
$$={\displaystyle \frac{20}{8\times 100}}$$
$$={\displaystyle \frac{20}{8}}\times {\displaystyle \frac{1}{100}}$$
$$={\displaystyle \frac{5}{2}}\times {\displaystyle \frac{1}{100}}$$
$$=2.5\times {\displaystyle \frac{1}{100}}=0.025$$
Hence, the required petrol to cover 1km is 0.025 lit.


Note: To divide a whole or a decimal number by 100, move the decimal point two places to the left. Note that although a whole number does not have a decimal point, we can always add it at the end of the number. (For example, 35 and 35. are the same numbers.) Also note that if there are not enough digits to move the decimal point the required number of places, we can always add extra zeros.