In a class of 40 students, $ \frac{1}{5} $ of the total number of students like to eat rice only, $ \frac{2}{5} $ of the total number of students like to eat chapati only and the remaining students like to eat both. What fraction of the total number of students like to eat both?

Given:

In a class of 40 students, \( \frac{1}{5} \) of the total number of students like to eat rice only, \( \frac{2}{5} \) of the total number of students like to eat chapati only and the remaining students like to eat both. 

To do:

We have to find the fraction of the total number of students who like to eat both.
Solution:

Fraction of students who like to eat both $=1-(\frac{1}{5}+\frac{2}{5})$

$=\frac{5-1-2}{5}$

$=\frac{2}{5}$
Therefore, $\frac{2}{5}$ of the total number of students like to eat both.