Probability that a leap year selected at random will contain 53 sundays is

A leap year has 366 days (or) 52 weeks and 2 odd days

The two odd days can be

$\left\{\left(\text{S,M}\right)\left(\text{M,T}\right)\left(\text{T,W}\right)\left(\text{W,Th}\right),\left(\text{Th,F}\right)\left(\text{F,Sat}\right)\left(\text{Sat,Sun}\right)\right\}$

So,

There are 7 possibilities out of

Which we have “2” Sundays

Number of favorable outcomes$n\left(E\right)=2$

Total out comes$n\left(S\right)=7$

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