"Open the door: Please answer all the questions on the stone platform." Yun Tianxun read out the words on the ceiling, and then pulled Feng Yu and walked quickly to the platform.

I saw that the stone platform was indeed engraved with shimmering words, and there was a small brush with a thin tip on the side.

There are three questions on the stone platform:

1. One hundred spirit beasts, every two have to fight each other, ask, how many times do these hundred spirit beasts have to fight?

2. Arrange ten different formation nodes in a row and ask, how many different formations are there?

3. As shown in the figure, how many forces does a stationary square spirit stone on a rough slope receive?

Seeing the first two questions, Yun Tianxun and Feng Yu glanced at each other, with smiles in their eyes.

This seemingly complicated calculation problem may be difficult for others, but for the array mage, it is a simple matter. After all, in addition to having the talent for formation and the ability to arrange formations, the most important thing for a formation mage is to calculate the formation, and the calculation of the formation involves extremely complex calculations.

Many times they have to go through all the possibilities from the spirit sense, and the question of how many times they ask any two of the hundred spirit beasts at one time, it seems to them that they are asking a hundred formation nodes, connecting two at will, and asking how many ways to connect.

Feng Yu quickly picked up the pen and wrote down a number after the two questions: 4950, 3628800.

"And what about this last question?" Yun touched his chin and looked at the picture attached to the third question. They had never encountered this kind of question of how many forces were received by the analysis.

"There is spiritual energy between heaven and earth, and all things are affected by spiritual power. First of all, the object on the inclined plane will receive the spiritual power between heaven and earth. Feng Yu lifted the pen and quickly dropped the word "spiritual power" on it. Zilang literature

"There should still be gravity." Yun Tianxun touched his chin: "People who have not attained the spirit master cannot fly against the wind in the Yinluo Continent, because their own spiritual power cannot overcome the effect of the earth's gravity on us. ”

"Since this spirit stone is subject to downward gravity, and there is an inclined plane blocking it at the bottom, then the inclined plane will give it a force to hold it up." Feng Yu added a "force on the slope to hold up the spirit stone" on it.

"The spirit stone on the inclined plane should slide down, but it says that it is stationary...... So that is, there is a force preventing it from sliding? Yun Tianxun looked at Feng Yu: "What kind of force is that?" Why does it exist? ”

Feng Yuzai carefully read the topic, and finally set his eyes on the word "rough", and then connected it with some of the usual life realities: "On the slippery hillside, even if people want to stand firmly, it is difficult for this spirit stone to slide down on the inclined plane, it should be because the inclined plane is rough." ”

"Then write a rough slope to give the force to the spirit stone." Yun said with a smile.

Soon, as Feng Yu put pen to paper, three doors opened in the palace.

And looking at these three doors, they all look like a red vortex.

"Where are you going?" Yun Tianxun raised his eyebrows and looked at Feng Yu, but he thought that this palace room was quite interesting.

Feng Yu looked at Yun Qianxun with a smile, took her hand and slowly walked towards the door in the middle: "In the middle." ”

Passing through the door, Yun Tilt and Feng Yu entered another palace.

And as soon as they entered the palace, countless spirit blades attacked them.

Fortunately, Feng Yu reacted quickly, and the moment he sensed the attack of the spirit blade, he waved his sleeve to scatter the spirit blade, and the two were not injured.