Question

A leap year is selected random then the probability that it will contain 53 sundays or 53 mondays

Answer 1

a leap year has 366 days ( 52*7+2)
so 52 weeks with 2 extra days
we need to find whether these 2 days will be Sunday or monday
so total outcomes =
Sunday Monday
Monday Tuesday
Tuesday Wednesday
Wednesday Thursday
Thursday Friday
Friday Saturday
Saturday Sunday
so outcomes = 7
Favourable outcomes (in which Sunday or Monday come) =3
so Probablilty = favourable outcomes /total outcomes
= 3/7

Answer 2

Answer:

In a leap year there are 366 days. In 366 days, we have 522 weeks and 2 days, Thus we can say that leap year ah always 52 Sundays.

The remaining two days can be

(i) Sunday and Mondays

(ii) Mondays and Tuesdays

(iii) Tuesday and Wednesday

(iv) Wednesday and Thursday

(v) Thursday and Friday

(VI) Friday and Saturday

(vii) Saturady and Sunday.

From above it is clear that there are 7 elementary events associated with this random experiment.

Clearly the event A will happen if the last two days of the leap year are either Sunday and Monday or Saturday and Sunday.

∴ P (E) = n (E)/n (S) = 2/7