Question

David’s mom paid \[\$2.40\] for a \[\dfrac{3}{4}\] pound box of a cereal. How much is that per pound?

Answer 1

Hint: Solving such types of problems is very easy once we get to know the underlying concepts behind the sum. To solve this sum quickly we need to have a fair amount of ideas of algebra, division and unitary method. The unitary method proposes that when we have some, say ‘x’ items at some price, say ‘y’ then we can very easily find out the price for a unit item by doing \[\dfrac{x}{y}\] . We can also find out how many units we will be getting for the unit price by doing \[\dfrac{y}{x}\] . We need to apply this particular process in this problem to get the answer smoothly.

Complete step by step solution:
Now we start off with the solution to the given problem by writing that,
We have \[\dfrac{3}{4}\] pound box of a cereal for \[\$2.40\] , we need to find the price required for a unit pound of the cereal. We can very easily find this value by dividing the right hand as well as the left hand side of the equation by \[\dfrac{3}{4}\] . This transformation will turn the left hand side of the equation to \[1\] unit or \[1\] pound. Thus our answer to the problem will be,
 \[=\dfrac{\$2.40}{\dfrac{3}{4}}\] Which evaluates to \[=\dfrac{4\times \$2.40}{3}=\$3.2\]

Note: For problems like these we need to be thorough about concepts of algebra and unitary method of elementary school. We must be very careful about what we are required to find in the given problem. If we are given to find the price of per pound then the price will be in the right hand side and the pound will be in the left hand side. Similarly if it was required to find the pound per unit price then the pound would have been in the right hand side and the price would have been in the left hand side.