Question

If half a litre of milk costs $22$ rupees, how much will $7$ litres cost?

Answer 1

Hint: Here first of all we will frame the fraction for half litre of milk and then will use multiplication to get the cost of $7$ litres of milk.

Complete step-by-step answer:
Given that: half a litre of milk costs $22$ rupees
Mathematical expression:
 ${\displaystyle \frac{1}{2}}$ liter of milk $=22$ rupees
 $7$ liters of milk $=?$
Perform cross multiplication, when one side of the term is multiplied with the opposite side of the other equations.
Cost $={\displaystyle \frac{7\times 22}{{\displaystyle \frac{1}{2}}}}$
Denominator’s denominator goes in the numerator.
Cost $={\displaystyle \frac{7\times 22\times 2}{1}}$
Simplify the above expression finding the product of the terms.
Cost $=308$ Rs.
Hence, the cost of seven liters of milk will be Rs. $308$
So, the correct answer is “Rs. $308$ ”.

Note: Always remember that if the amount of one unit is given and asked to find the amount of many then always use multiplication for one to many and use if the total amount is given and you know the amount of one unit then we can get the number of units by using the division. Be good in multiples and division and be careful about the decimal points when direct division is not possible.