[jaclaz]

>The "wrong" way to solve this problem is to compute hen-laying in terms of hen-egg-days, and then scaling.

I am not sure to understand what you mean by "wrong" way, I got the right result through a different reasoning that seems to me based on hen-egg-days.

It takes 3 days for 3 hens to make 3 eggs.

The 3 days time are "fixed", i.e. it takes 3 days for each hen to make its own egg.

The egg production rate is 1/3 egg per day per hen.

So I have 12 hens x 12 days x 1/3 = 144 x 1/3 = 48