Every healthy duck is greedy and every old duck is greedy.
On a particular farm, some ducks are greedy and some ducks are not.
Which of the following statements about the ducks on that farm must be true?
This problem is taken from "Sums for Smart Kids" by Laurie
Buxton, published by BEAM Education.
To obtain a copy call the BEAM orderline on $020 7684 3330$. (Price: $£17.50$ plus handling and delivery.)