Question

Find the probability of having 53 Sundays in a leap year.

Answer 1

Number of days in a leap year = 366

i.e. a leap year has 52 weeks and 2 days.

There is no doubt of having 52 Sundays in 52 weeks.

Thus, we have to find the probability from the remaining 2 days only. These 2 days can be {(Sa, S), (S, M), (M, T), (T, W), (W, Th), (Th, F), (F, Sa)}

No. of favourable outcomes is 2 i.e. {(Sa, S), (S, M)}

Total no. of possible outcomes = 7

Therefore P(53 Sundays) = $\frac{2}{7}$