When a leap year is selected at random then the probability that it has exactly 52 Sundays is

The question is asking the probability of getting "exactly" 52 Sundays and not at least 52 Sundays.

There are 52 weeks in a year, so there will be 52 Sundays, no doubts  about it. However, 52 $$\times$$ 7 = 364 days  

 so that still leaves a day for a normal year, and two days for a leap year.

Now, let us look at the combinations of the two days possible.

(Sunday, Monday), (Monday, Tuesday), (Tuesday, Wednesday), (Wednesday, Thursday), (Thursday, Friday), (Friday, Saturday), (Saturday, Sunday)

Now, to get exactly 52 Sundays, none of the last two days should be a Sunday. As you can see from the combinations listed above, that is possible in 5 out of 7 cases. So the Probability would be 5/7.       Answer