Answer
a)$\frac{1}{365}$
b)$\frac{31}{365}$
c) 0.01
d)really unlikely
Work Step by Step
a) We know that $probability=\frac{number \ of \ good \ outcomes}{number\ of\ all\ outcomes}$, hence $P(October / 18)=\frac{1}{365}.$
b) We know that $probability=\frac{number \ of \ good \ outcomes}{number\ of\ all\ outcomes}$, hence $P(October)=\frac{31}{365}.$
c) Americans who have Japanese roots are most likely to know when the National Statistics Day is in Japan. If we estimate the Americans with Japanese roots by subjective probability, then it is 1%=0.01.
d)Hence by the result of c) it is really unlikely to select someone who knows when the National Statistics Day is in Japan because 0.01 is really close to 0.
