4d wrote:
Find the probability that a randomly selected year has 53 Sundays.
A) \(\frac{1}{7}\)
B) \(\frac{2}{7}\)
C) \(\frac{3}{7}\)
D) \(\frac{3}{28}\)
E) \(\frac{5}{28}\)
Total days in year = 365 or say 52 weeks and 1 day
Total days in leap year = 366 days or say 52 weeks and 2 days
so P of sunday in non leap year = 1/7
and P of sunday in leap year = 2*1/7 ; reason why since we have a day extra in a leap year so chances are that sunday can be on that extra day
P of a leap year is 1/4 and non leap year is 3/4
so for sunday
1/4*2/7 + 3/4*1/7
2+3/28 ; 5/28
IMO E
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