Choose the best preposition in the given sentence.
He travelled around the world _____ eighty days.

- In is used to express a period of time during which an event happens or a situation remains the case.
- From is used to indicate a starting point.
- Under means lower than (a specified amount, rate, norm, or age).
- For is used to indicate a purpose.
- Clearly, the correct preposition is 'in'.
- Correct sentence: He travelled around the world in eighty days.