Three 24 hour days, but it can be four days, for example: from Monday 12:00 till Thursday 12:00 is 4 day:

- Monday (12)

- Tuesday (24)

- Wednesday (24)

- Thursday (12)

72 Hours is equal to 3 days.

In exact, 72 hours is equal to 3 days and 11.8 minutes, as 1 rotation of earth takes about 23 hours 56 minutes and 4 seconds!

72 hours equal to 3 days, there is 24 hours in a day so if you multiply 24 by 3 you will get 72 hours or you can divide 72/24 then you will get 3.

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