2. There is such a question in the world-famous arithmetic book "Nine Chapters of Arithmetic": "Today, those who are good take a hundred steps, and those who are not good take sixty steps. Today, the bad ones should take a hundred steps first, and the good ones should catch up later. What are the geometric steps? " It means that when the fast runner takes 100 steps, the slow runner only takes 60 steps. Slow walkers go first 100 step. How many steps does the runner have to take to catch up?
3. Another famous title in Sun Tzu's Art of War: "There is wood today, but I don't know its length. What is the length of the wood? " It means: measure a long piece of wood with a rope. The rope is still 4.5 feet. Fold the rope in half and measure the long piece of wood. The long piece of wood is still 1 foot. How long is the long wood?
4. Cheng Dawei, a famous mathematician in Ming Dynasty, wrote a question: "100 monks are divided into 100 steamed buns, the big monk eats three, and the little monk eats every three 1 piece. Ask the big monk and the little monk how much. "
5. A well-known math topic circulating among the people in our country: I only heard that the people next door were given money, but I don't know how many money and people there are; 7 per person under two, 7 per person, half a catty and half a person; Excuse me, good calculators, how many people share how much silver? (Note: Gold here refers to gold, 1 gold = 10 Liang).