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The probability of not getting 53 Sundays in a leap year is

Solution

✅ Correct Option: 4

A leap year has 366 days.

Dividing 366 by 7:

366 ÷ 7 = 52 weeks + 2 extra days


Since there are 52 complete weeks, there are guaranteed to be 52 Sundays.

Whether there is a 53rd Sunday depends on the 2 extra days.


The 2 extra consecutive days can be any of these 7 combinations:

  1. (Sunday, Monday)
  2. (Monday, Tuesday)
  3. (Tuesday, Wednesday)
  4. (Wednesday, Thursday)
  5. (Thursday, Friday)
  6. (Friday, Saturday)
  7. (Saturday, Sunday)

Out of 7 possible combinations, Sunday appears in 2 combinations: (Sunday, Monday) and (Saturday, Sunday).

Probability of getting 53 Sundays =27= \frac{2}{7}


Probability of NOT getting 53 Sundays:

=1−27= 1 - \frac{2}{7}

=7−27= \frac{7-2}{7}

=57= \frac{5}{7}

Therefore, the probability of not getting 53 Sundays in a leap year is 57\frac{5}{7}.

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