Contribution on Puzzlet #178
From: Klaas R. Visser (firstname.lastname@example.org)
I cannot find the fact from which could be deduced "that the father was at least 21 when he married" in the description of the problem.
So I found another solution: 24, 19 and 4 years.
Klaas R. Visser.
Thanks very much for this input. Your extra solution is correct.
The reason I fixed the father's age at 21 or greater is due to the fact that his wife is 5 years younger, making her minimum possible age 16. In the western world, marriage is illegal below 16.
However, that's not the reason that my code didn't find the fourth solution. It's due to a simple typo! The line "until pa - twin < 21" should read "until pa - twin < 20". When you run the code with this correction, the fourth answer is included.
I'll publish this and give you the credit for finding the extra solution - well done, and thanks again.