Soon after Zhuge Liang led the army to camp in Dingjun Mountain, Sima Yi learned that Zhuge Liang had few military forces and prepared to surprise Zhuge Liang's barracks.
One evening, Sima Yi's soldiers will begin to move down from Tiandang Mountain. At this time, Zhuge Shijun was reading Sun Tzu's Art of War under the lamp, and suddenly he came to report that Sima Yi was leading a team to attack the barracks. After hearing this, Zhuge Liang gently shook the feather fan in his hand a few times, stood up, paced back and forth in his tent, and then. Call in Guan Xing and Zhang Bao to discuss countermeasures. Zhang Bao said: "The enemy will block you and the water will drown you. You should immediately send troops to fight, and you are willing to fight the Sima thief to the end! " Guan Xing went on to say, "Sima Yi has many soldiers, and we in Serenade are outnumbered. I don't think we can fight to the death! " Zhang Bao said: "Seeing that the fire is about to burn to the brow, what can you do if you don't work hard?" Oshima Geliang then slowly shook the feather fan a few times and said with a smile; "Manpower, think about it, don't have a way. I have a little plan. I wonder if it is feasible? " Guan Yu and others asked urgently, "What's the clever plan? Please tell me quickly! " Zhuge Liang said unhurriedly, "I order you to take three thousand men each, and ambush in front of and behind the mountain during the second watch." Then I set a question, as long as the left-behind soldiers count once a night.
In my opinion, Sima Yi and Sima Er dare not make my camp. Guan He quickly said, "Please ask the strategist to give a question!" ! "Zhuge Liang said while gesticulating," There are a flock of sheep at home, a total of 15 pairs. It is forbidden to slaughter them for seven days, except for single sheep. How many animals are slaughtered on average every day? There are many rewards for answering correctly. "I heard that, the second commander looks like a two-foot-tall monk-scratching his head. It's not convenient to ask again now, so I have to obey. That night, all the barracks were lit with candles, and the soldiers stayed up all night, calculating the questions given by their teachers.
In the middle of the night, Sima Yi led an army and headed for Dingjun Mountain. He crossed the Han River and looked south. Dingjun Mountain is brightly lit everywhere, just like the shining stars in the sky. Afraid of being caught, he quickly ordered to retreat.
At dawn, the banks of the Han River are safe. General Zhang Guan came to the tent and bowed to Zhuge Liang and said, "The soldiers thought about your problem all night and said," Kill four, four, seven, two, five, seven, thirty-five and five again every day. " Well, it's not right yet! "Zhuge Liang said with a smile," OK, OK! " Zhang Guan first one leng, after thinking for a while, they all burst out laughing.
There is no solution to this problem, and the sum of seven odd numbers can't be even.