3. Ducks were flying. One in front, two behind, one behind and two in front, one between two and three in a row. How many ducks were flying in total?
3. Let's schematically depict how the ducks flew.

![](https://cdn.mathpix.com/cropped/2024_05_21_e53d4ff4f2278a1c0d12g-031.jpg?height=309&width=811&top_left_y=608&top_left_x=628)

As can be seen from the diagram, the problem is about three ducks.

Answer: 3 ducks.