Question

Geeta read $\dfrac{3}{8}$ of a book on one day and $\dfrac{4}{5}$ of the remaining on another day. Find the portion of the book left unread after one day.
A.$\dfrac{5}{8}$
B.$\dfrac{7}{6}$
C.$\dfrac{5}{4}$
D.$\dfrac{7}{2}$

Answer 1

Hint: Here, we are taking the total portion of the book read is 1. Since we are given that the portion of book read on one day is $\dfrac{3}{8}$, then the portion of book left unread after one day will be the difference of total portion of the book read and the portion of book read on one day.
Complete step by step answer:
We are given that Geeta reads $\dfrac{3}{8}$ of a book on one day and $\dfrac{4}{5}$ of the remaining on another day.
Now, we have to find the portion of the book left unread after one day.
Let the total portion of the book read by Geeta be 1.
The portion of book read on one day = $\dfrac{3}{8}$
The portion of book left unread after one day = 1 – The portion of book read on one day.
The portion of book left unread after one day = $1-\dfrac{3}{8}$
By taking the LCM we can say that,
The portion of book left unread after one day = $\dfrac{8-3}{8}$
The portion of book left unread after one day = $\dfrac{5}{8}$
Therefore, we can say that $\dfrac{5}{8}$ of the book will be left unread after one day.
Hence, the correct answer for this question is option (a).

Note: Here, the number is not given, only the fraction is given. In such cases, you have to consider the whole fraction, which is 1. In the question they are asking to calculate the portion of book left unread after one day, so you have to consider only $\dfrac{3}{8}$ and $\dfrac{4}{5}$ of the remaining is read on second day which should not be considered.