Any irrational number when added
to 2 / 5 still produces an irrational number.
For example, if we use π to add to 2/5
or 0.4. As far as we know the decimal digits for π just go on forever and do not
have a repeating cycle hence making it an irrational number. Adding a rational
number such as 0.4 to
the value of π
does not really greatly change the value of π. The decimal digits (hundredths place and so on) of
the resulting number will still go on forever without a continual repeat.
So 0.4 + π is
still irrational