Probably got it from here -
GM1 FCL.1015 Examiner Standardisation
(c) When planning the duration of a test, check or assessment of competence, the following values may be used for guidance:
(1) 45 minutes for a LAPL(B) or BPL and SP class ratings VFR only;
(2) 90 minutes for LAPL(A) or (H), PPL and CPL, including navigation section;
(3) 60 minutes for IR, FI and SP type or class ratings;
(4) 120 minutes for CPL, MPL, ATPL and MP type ratings.
45 minutes for the VFR elements of the MEP class rating and 60 minutes for the IR will give you the quoted 1.45 but they obviously missed the
may (not must or should) be used for
guidance.