Question

Ananya had $\dfrac{3}{4}$ L of milk. She used $\dfrac{1}{5}$L to make a cup of tea. How much milk did she have left?
(A) $\dfrac{1}{4}L$
(B) $\dfrac{{11}}{{20}}L$
(C) $1\dfrac{1}{4}L$
(D) $\dfrac{1}{2}L$

Answer 1

Hint: We need to read the question carefully. Here, quantity of milk is given. And it is to be used to make a cup of tea. So, to find the amount of milk that is left, we have to simply subtract the quantity of milk left from the total quantity of milk Ananya had, thus it can be obtained by simply subtraction.

Complete step-by-step answer:
Remaining quantity of milk should be equal to difference of quantity of milk she had & quantity of milk she used for making tea i.e.,
Remaining quantity of milk= Total quantity of milk she had – Quantity of milk she used to make tea
Given, Ananya had $\dfrac{3}{4}L$ of milk.
$\dfrac{1}{5}L$ of milk is used to make a cup of tea.
$\therefore $ So as stated before , remaining quantity of milk= Total quantity of milk she had – Quantity of milk she used to make tea
 = $\dfrac{3}{4} - \dfrac{1}{5}$
$ = \dfrac{{15 - 4}}{{20}} = \dfrac{{11}}{{20}}L\left( B \right)$.
Option B is the correct answer.

Additional Information:
Fractional numbers are subtracted by following some steps:
To subtract fractions there are three Simple Steps:
Step 1: Make sure the bottom numbers (the denominators) are the same, if they are not the same find the L.C.M of those numbers.
Step 2: After making the denominators the same perform the required mathematical operation to the numbers in the numerator.
Step 3: Simplify the fraction (if needed)

Note: In this type of problem the left amount can easily be calculated just by subtracting the used quantity from the given quantity of milk. Do the calculation carefully to avoid mistakes. Also in these types of questions the final answer will always be positive.