How many ways can you choose three books from four books by different authors?

1. According to the problem statement, 4 books by different authors are given.
You need to choose three of them and count the number of options for such a choice.
Let’s designate each selected book with its own number 1, 2, or 3.
2. Any of the four given books can be substituted for the first book – 4 options of choice.
In place of the second book – any of the three remaining – 3 options.
Two books claim to be the third book – 2 options.
3. Let’s count the number of combinations.
4 * 3 * 2 = 12 * 2 = 24.
Answer: 3 books out of 4 books can be selected in 24 ways.