Find the probablity that a leap year contains
(i) 52 sundays 

(ii) 53 sundays

leap year contanins $366 days=52\left(W\right)+2\left(D\right)$
$n\left(S\right)=7days$

(i) leap year contains 52 sundays
The probability of leap year contains 52 sundays
the remaing 2 days ={(M,Tue) (Tue,Wed) (Wed,
Thu)(Thu, Fri)(Fri, Sat)}

$\mathrm{n}\left(\mathrm{E}\right)=5;n\left(S\right)=7;P\left(E\right)=\frac{n\left(E\right)}{n\left(S\right)}=\frac{5}{7}$

(ii) Leap year contains 53 sundays
The remaining days ={(Sun, Mon) (Sat, Sun)}

$\mathrm{n}\left(\mathrm{E}\right)=2;$   $P\left(E\right)=\frac{n\left(E\right)}{n\left(S\right)}$    $=\frac{2}{7}$