A hen and a half

Henry Dudeney called it an old friend in 1926. It was in print by 1888.

29 Mar, 2026

If a hen and a half lays an egg and a half in a day and a half, how many eggs do six hens lay in six days?

Give me a hint

First work out how many eggs a single hen lays in a single day.

Reveal the answer

24

A hen and a half lays an egg and a half in a day and a half, so a single hen lays an egg in a day and a half. That’s two thirds of an egg a day. Six hens for six days is 36 hen-days, and two thirds of 36 is 24.

Source: Traditional, in Henry Dudeney, Modern Puzzles, 1926, No. 79