chickens and eggs problem

I just came across this old problem:

If one and a half chickens lay one and a half eggs in one and a half days, how many eggs do nine chickens lay in nine days?

Everywhere I've looked people work it out mathematically as 54 eggs, but I work it out logically as 81 eggs.

The problem is, most people ignore the realities of the situation. An egg can be half laid, and a half a day is a perfectly useful unit of time, but half a chicken is useless and can't lay anything, so one chicken has to be laying the one and a half eggs in one and a half days, which is the same as one chicken laying one egg per day. So 9 chickens over nine days produce 81 eggs.

(Crossposted from http://miriam-e.dreamwidth.org/324418.html at my Dreamwidth account. Number of comments there so far: )