1 .
Annie, Boris, and Charlie have random and independent birthdays. (We ignore leap years, so that a
year has 365 days.) What is the probability that Annie, Boris, and Charlie have the same birthday?
(a)
$\frac{365}{364^{2}}$
(b)
$\frac{1}{364 \cdot 365}$
(c)
$\frac{1}{365^2}$
(d)
$\frac{1}{365^{3}}$