Question

The cost of 1 litre petrol is Rs.72.65. What is the cost of 15.5 litres of petrol?

Answer 1

Hint: In these types of questions in order to determine the cost of $x$ litres of petrol, we have to multiply the cost of one litre of petrol with $x$. So here to find the cost of 15.5 litres of petrol we have to multiply the cost of one litre of petrol with 15.5, then we will get the required answer.

Complete answer:
Given that the cost of 1 litre petrol is of Rs.72.65 and here we have to find the cost of 15.5 litres of petrol.
Now since we know if we have to determine the cost$x$litres of petrol, we have to multiply the cost of one litre of petrol with$x$.
So here to find the cost of 15.5 litres of petrol we have to multiply the cost of one litre of petrol with 15.5.
Here cost of 1 litre of petrol = Rs.72.65.
Thus, the cost of 15.5 litres of petrol can be determined by multiplying 15.5 with the cost of 1 litre of petrol i.e., 72.65.
$ = 15.5 \times 72.65$
Now by multiplying both the numbers we get,
$ = \dfrac{{155}}{{10}} \times \dfrac{{7265}}{{100}}$,
$ = \dfrac{{1126075}}{{100}}$
Now transforming the answer in decimal form we get,
$ = 1126.075$.
Thus the cost of 15.5 litres of petrol will be Rs.1126.075.
Final Answer:
Thus we got the cost of 15.5 litres of petrol by multiplying the cost of 1 litre of petrol with the given litres which cost is to be determined.

$\therefore $ The cost of 15.5 litres of petrol will be of Rs.1126.075.

Note:
In these types of calculations we need to be careful with the transformation into decimal form as the number of zeros in the denominator should be observed carefully without getting confused.
For Example:$\dfrac{{2507}}{{100}} = 25.07$, denominator has two zeros then the decimal should move to two points.