## 29. Leonie and Cats

When old lady Leonie is asked how many cats she has, she melancholically replies: “Four fifths of my cats plus four fifths of a cat.” How many cats does she have?

![](https://cdn.mathpix.com/cropped/2024_05_21_fe999c0fe2ad81fc5164g-072.jpg?height=663&width=916&top_left_y=1459&top_left_x=570)
29. Let $n$ be the number of cats Leonie has. From her last words, we can write the relationship

$$
n=(4 / 5) n+4 / 5, \text { i.e. } \quad n=4 .
$$

Thus, Leonie has 4 cats.