Question

A cup is $\dfrac{1}{3}$full of milk. What part of the cup is still to be filled with milk to make it full?

Answer 1

Hint: To solve such questions start by writing the total volume of the cup to be filled. Then the part of the cup that needed to be filled for the cup to be full will be equal to the total volume minus the part of the cup filled with milk.

Complete step-by-step solution:
Given that $\dfrac{1}{3}$part of the cup is full of milk.
It is asked to find the part of the cup to be filled to make it full.
It is known that the total volume of the cup is $\dfrac{3}{3}$.
That is,
The volume of the cup $ = 1$
Therefore,
The part of the cup that needed to be filled to make it full = total volume of cup - part of cup filled with milk.
$ = 1 - \dfrac{1}{3}$
Next, take the LCM. That is,
$ = \dfrac{{3 - 1}}{3}$
Simplifying further we get,

The part of the cup that needed to be filled with milk to make it full $ = \dfrac{2}{3}$.

Additional Information: Proper fractions are those fractions in which the numerator is smaller than the denominator. Improper fractions are those fractions in which the numerator is greater than the denominator. When the numerator and denominator of a fraction do not have any other common factor other than one then the fraction is said to be in its simplest form. While adding more than one fraction together first we have to add the numerator keeping the denominator as such.

Note: Always remember while subtracting unlike fractions, we have to find a common denominator of the two fractions, and then we have to subtract it. Also, remember that fraction means a part of the whole object.