It's already in simplest form.
2/5 is its simplest form
2/5 is already in simplest form. You cannot reduce it to 1/2.5 because a fraction cannot have a decimal for either the numerator or the denominator.
2/5 Is in it's simplest form.
It is already in its lowest term/simplest form.
2/5 = 4/10 = 0.4
2/5 is already in its simplest form.
2/5 is as simple as it can get so there really is no simplest form because it's already in simplest form.