Henry Ernest Dudeney/Puzzles and Curious Problems/164 - Cow, Goat and Goose

by : $164$

 * Cow, Goat and Goose
 * A farmer found
 * that his cow and goat would eat all the grass in a certain field in $45$ days,
 * that the cow and the goose would eat it in $60$ days,
 * but that it would take the goat and the goose $90$ days to eat it down.


 * Now, if he had turned cow, goat and goose into the field together, how long would it have taken them to eat all the grass?


 *  showed us how to solve a puzzle of this kind with the grass growing all the time;
 * but, for the sake of greater simplicity, we will assume that the season and conditions were such that the grass was not growing.