The formula of pigeon nest problem is summarized as follows: number of objects ÷ number of pigeon nests = quotient ... remainder, at least number = quotient+1.

Put m objects into n pigeon nests at will (m and n are nonzero natural numbers, 2n > m > N), then there must be at least two objects in a pigeon nest. If more than kn objects are randomly divided into n pigeon nests (k and n are non-zero natural numbers), there must be at least (k+ 1) objects in a pigeon nest.

explain

Put four pens in three pen containers. There are always at least a few pens in one pen container.

1, number of objects found -4, number of drawers found -3.

2. All the cases of putting four pens (number of objects) into three pen containers (drawers) are listed.

Draw a conclusion that there is always a pen container (drawer) with at least two pens in it.

4. Find the law: When the number of objects is more than the number of drawers 1, there are always at least two objects in a drawer.