the probability for a leap year to have exactly 52 mondays is

In a leap year there are 52 weeks, and two remaining days.

Those two days are consecutive, so there can 7 equally likely pairs.

Among the 7 pairs, (Sunday, Monday) and (Monday, Tuesday) pair will result in 53 Mondays.

So unfavourable pairs are these 2, rest (7–2=5) pairs are favourable.

So the probability = 5/7