This is a question of permutation and combination. Choose two of the three books and give them to two people. The formula is A32=6.

It can also be solved by enumeration. Let three books become ABC. AB, AC, BC, BA, CA, CB, ***6 kinds.

Extended data:

Classification of permutation and combination problems;

1. Calculate the number of ways to group certain items under certain conditions. These are about permutation, combination and integer division.

2. Map coloring: Color the map of the world, with one color for each country. If neighboring countries are required to have different colors, do they always need only four colors?

3. The boatman crosses the river: The boatman wants to transport a wolf, a sheep and a cabbage across the river. As long as the boatman is away, the sheep will eat cabbage and the wolf will eat the sheep. The boatman's boat can only hold one thing at a time. How to transport everything across the river.

4. The postal route problem in China was put forward by Professor Guan Meigu, a combinatorial mathematician in China. The postman has to cross every road in the city at least once, how to take the shortest distance.

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