Answer :

Louli
Answer:
[tex] \frac{2}{5} [/tex]

Explanation:
A fraction is said to be in the simplest form if there is no common factor between the numerator and the denominator.

In the given fraction, 
[tex] \frac{40}{100} [/tex] , we can note that both the numerator and the denominator can be divided by 10.

This will give us:
[tex] \frac{4}{10} [/tex]

Now, we can note that both the numerator and the denominator in 
[tex] \frac{4}{10} [/tex] can be divided by 2

This will give us:
[tex] \frac{2}{5} [/tex]

The aren't any common factors between the 2 and the 5, therefore, 
[tex] \frac{2}{5} [/tex] is the simplest form of the given fraction.

Hope this helps :)