Problem 8. On one face of a die, one dot is drawn, on another face - two, on the third - three, and so on. Four identical dice are stacked as shown in the figure. How many dots in total are on the 6 faces where the dice touch?

![](https://cdn.mathpix.com/cropped/2024_05_06_1fc2a67343dfc685efebg-3.jpg?height=245&width=700&top_left_y=346&top_left_x=678)

Answer: 20 dots.
Solution. Note that on the faces adjacent to the three, there are one, two, four, and six. Therefore, five and three are on opposite faces. Then, adjacent to the one are two, three, five, and six. Therefore, one and four are on opposite faces. From this, two and six are also on opposite faces.

If we look down at the last cube, we will see one, and on the side faces in clockwise order, there will be six, three, two, and five. Then on the left face of the first cube, there should be three dots, and on the right - five.

On the second cube, the side faces have four dots and one dot. On the third cube - six dots and two dots. On the left face of the fourth cube, there are two dots. Then the desired sum is $5+(4+1)+(6+2)+2=20$.

![](https://cdn.mathpix.com/cropped/2024_05_06_1fc2a67343dfc685efebg-3.jpg?height=403&width=531&top_left_y=1266&top_left_x=771)