A leap year has 366 days

366 days = 52 weeks + 2 days

That 2 days may be (Sun, Mon) , (Mon, Tue) , (Tue, Wed) , (Wed, Thu) , (Thu, Fri) (Fri, Sat) , (Sat, Sun)

Let E ⟶ event of getting 53 Sundays & 53 Mondays.

No. of favourable outcomes = 1 {(Sun, Mon)}

Since 52 weeks has 52 Sundays & 52 Mondays & the extra 2 days must be Sunday & Monday.

Total no. of possible outcomes = 7

P(E) = (No.of favorable outcomes)/(Total no.of possible outcomes) = 1/7