CAS 6: Earned and Unearned Premiums

[Tex Act]

In the example for calculating the pro-rata unearned prem, why is the semi-monthly prem factor 13/24 instead of 11/24?

It seems to me that if the eff. date is July 1 and you are evaluating as of Dec. 31 then you have 6 months with the first month only earning 1/24:

July 1/24
Aug 3/24
Sept 5/24
Oct 7/24
Nov 9/24
Dec 11/24

So why do they have 13/24?

[Been There Done That]

Just like you observed, during the first 6 months you earn 11/24, this leaves 13/24 unearned.

[Tex Act]

Ha ha! Just testing you.

Really.