My work.

Option A: Sufficient.

All the numbers in the list are integers. No intergers when added give any decimal result. Hence the Median has to be something that was divided by 2. (Say 72 and 77, 73 and 74, 70, and 77)

So the series goes...................(14 numbers) 70, 77 (14 numbers)= hence 73.5. (So number of days=30)

If the number of days were 31, then 30 numbers would have been crossed off and we will be left with one value, which is definitely an integer.

Option B: Not sufficient

hence option A the answer.

Bunuel wrote:

A list kept at Town Hall contains that town's average daily temperature in Fahrenheit, rounded to the nearest integer, for each day of a particular completed month. Does this month have 30 or 31 days?

(1) The median temperature is 73.5.

(2) The sum of the average daily temperatures is divisible by 3.

Kudos for a correct solution.

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Kudos to you, for helping me with some KUDOS.