A, B and C are all reading the same book, which contains 100 stories. Everyone starts with a story and then reads it in order. It is known that A has read 75 articles, B has read 60 articles and C has read 52 articles. So how many stories have A, B and C read? First of all, we can look at two of them, such as A and B. In order to ensure that both of them read as little as possible, we must first try different reading methods, so both of them read at least 75+60- 100=35 stories, and then C read 52 stories. First of all, he should try not to read the same as these 35 stories, but to be related, so he should try to read them in A.2. There are three mountains and five mountains in China, among which the five mountains refer to Mount Taishan in Dongyue, Mount Hengshan in Nanyue, Huashan in Xiyue, Mount Hengshan in Beiyue and Songshan in Zhongyue. A teacher took photos of the five mountains and marked them with numbers. He asked five students to distinguish them. Each student names two, and the students answer as follows: A: 2 is Songshan, 3 is Huashan, and B:. The teacher found that all five students were only half right, so what should be the correct statement? Answer: If the first half of A is correct and the second half is wrong, then 2 is Mount Tai and 3 is not Huashan; Because everyone said half sentence is right and half sentence is wrong, it can be concluded that the first half sentence of E is wrong and the second half sentence is right, that is, 2 is not Huashan and 5 is Taishan. This contradicts A's saying that "2 is Mount Tai", so the assumption is wrong. So we can know that the first half of what A said is wrong and the second half is right, that is, 3 is Huashan; From what Wu said, the second is not Huashan, and the fifth is Taishan; According to C, 5 is not Mount Tai, 1 is Hengshan; From b, 4 is not Hengshan, 2 is Songshan; According to Ding, 3 is not Songshan Mountain and 4 is Hengshan Mountain, so the correct statement is: 1 is Hengshan Mountain, 2 is Songshan Mountain, 3 is Huashan Mountain, 4 is Hengshan Mountain and 5 is Mount Tai. 3. Prove that++is between and. × 10 = C). Why? If B=C, the defective product is in A, and the defective product is heavier than the genuine product. Then take out two balls in A and weigh them, and you can draw a conclusion. If b < c, you can also draw a conclusion before imitation. (3) if a < b, similar to the case of a > b, we can draw a conclusion through analysis. 35. Figure (1) and Figure (2) are two large rectangles with the same shape and size. As shown in Figure (3), four small rectangles are placed in each large rectangle, and the diagonal area is empty. It is known that the length of a large rectangle is 6 cm wider than its width. Q: Figure (1) and Figure (2). How much bigger? Analysis: The circumference of diagonal area in figure (1) is exactly equal to the circumference of large rectangle, and the circumference of diagonal area in figure (2) is obviously smaller than that of large rectangle. The difference between the two is 2? AB. Seen from the vertical direction of Figure (2), AB = A-CD In Figure (2), the length of the rectangle is A+2B and the width is 2B+CD, so (A+2B)-(2B+CD) = A-CD = 6 (cm). Therefore, the circumference of the diagonal area in the figure is (1). 36. Find the area of trapezoidal ABCD in the figure, where BC=56 cm. (unit: cm) solution: According to the trapezoidal area formula, there are: s ladder = 1/2×(AB+CD)×BC, and because triangles ABC and CDE are isosceles right triangles, AB=BE, CD=CE, that is, s ladder = 1/2× (AB+). . . . . 1()222。 . . . . . 2. () is preceded by 100 1s, and () is followed by 100 2s, which can be divisible by 13. What's the number in ()? 138, there are several red balls and white balls. If 1 red balls and 1 white balls are taken out at one time, when the red balls are finished, there are still 50 white balls left. If you take/kloc-0 red balls and 3 white balls at a time, and there are 50 red balls left when the white balls are taken away, how many red balls and white balls are there? (3× 50+50) ÷ (3-1) =100-red 100+50= 150_ white100+1. If "music" stands for "9", then "I" stands for _ _, "number" stands for _ _, and "learning" stands for _ _. Solution: "Le" stands for 9, and it can be deduced that "Xue" stands for 1 and "number" stands for 6; The product is ten digits, and the first two digits are all 6, so it can be inferred that "I" stands for 8. Note: This question is a change in the form of a question written by Mr. Tan on May 25th 1992. To infer what numbers "music", "learning" and "number" represent respectively, we can get the result immediately by using the knowledge of "square mantissa property of natural numbers" and carry. It will be a bit difficult to push "I" a few more times. Valuation method is needed: because 800002 < 666161161< 900002, 8≤ I ≤9. Obviously, "I" can only be 8. 42. On a long wire, the yellow beetle climbs from the right end to the left end at a speed of centimeters per minute, while the red beetle and the blue beetle climb from the left end to the right end at a speed of centimeters per minute. When is the red beetle right between the blue beetle and the yellow beetle? At 8: 30, the distance between the yellow beetle and the left end is1200-15 *10 =1050 (cm). After another t minutes, the red beetle is between the blue beetle and the yellow beetle. At this time, the distance between the red beetle and the blue beetle is (13-1) t cm, and the distance between the red beetle and the yellow beetle is [1050-(13+15) t] cm, and the equation can be obtained: (. So 35 minutes from 8:30, that is, 9:05, the red beetle is right between the blue beetle and the yellow beetle. 43. A list of numbers, what is the sum of all the scores of these 239 numbers that are not integers? Analysis: It will be difficult to find non-integers directly and then add them up. You can think of it another way, first add them all up and then subtract the whole number! Is an integer, and the molecule must be a multiple of 12, and in 1~239, the multiple of 12 is 12, 24, 36, 48...228. So, the sum of all the scores is

Hope to adopt!