Question

find the probability that a not a leap year contains 52 sunday

Answer 1

here the answer is 1/7

Answer 2

A non leap year has 365 days, so, we can have 52 weeks (52 x 7=364 days) and we're left with one day extra (365–364=1). This day can be any one of the seven different days and since we already had 52 Sundays because we already completed 52 weeks, we don't want this extra day to be a Sunday. So, the no. of favorable days are 6 and total possibilities are 7. This the answer is 6/7.

The scenario would be different for a leap year because there we've 366 days leaving 2 extra days. This two extra days can come in any one of pair from the following pairs {(sun, mon),(mon, Tue),(Tue, Wed),(Wed, thu),(thu, Fri),(Fri, sat),(sat, sun)} here the Sunday doesn't appear in 5 pairs, so, the probability for a leap year to have 52 Sundays would be 5/7.