Question

Find the probability that a leap year selected at random will contain 53 Sundays.

Answer 1

A leap year has 366 days with 52 weeks and 2 days.

Now, 52 weeks conatins 52 sundays.

The remaining two days can be:

1. Sunday and Monday
2. Monday and Tuesday
3. Tuesday and Wednesday
4. Wednesday and Thursday
5. Thursday and Friday
6. Friday and Saturday
7. Saturday and Sunday

Out of these 7 cases, there are two cases favouring it to be Sunday.

∴ P(a leap year having 53 Sundays) = `("Number of favourable outcomes")/"Number of all possible outcomes"`

`= 2/7`

Thus, the probability that a leap year selected at random will contain 53 Sundays is `2/7`.