Henry Ernest Dudeney/Puzzles and Curious Problems/119 - The Three Drovers/Solution

by : $119$

 * The Three Drovers

Solution
Jack had $11$ animals, Jim had $7$, and Dan had $21$.

Proof
Let $a$, $b$ and $c$ be the numbers of animals in each of Jack's, Jim's and Dan's droves respectively.

We have: