Eternity in an hour

Bronwyn's pulling her hair out trying to work out the leave entitlement for one of the new Relief Assistants. She asks me for help (desperate woman). The problem lies in the model examples provided by Human Resources:

Jane works 20 hours per week. Her entitlement is:

20 / 37.5 x 140
= 74.6666 hours' holiday
= 75 hours 6 minutes

Between us it took us ten minutes to realise just what the problem is here. And another ten to believe it had become official mathematics.

*(To spare you our agonies: .66 of an hour is not sixty six minutes)