Information about contiguous format and non-contiguous format with extents?

Question

List the information required to access a record in a file arranged as follows:

a) The file is stored in a simple contiguous format.
b) The file is stored in a non-contiguous format with extents.

Answer 1

What sort of file? Fixed records? Variable records with bytecounts? Variable records with delimiters?

The contiguity of the file is not the only factor.