26. The era of A, B and C-D is now. When A is 2 1 year, B is 17 year, A is 18 year, C is three times that of D, and how old is D now?
27. There are three people in a family. My father is three years older than my mother. Now their ages add up to 80. 10 years ago, the total age of the whole family was 5 1 year. So, how old is my daughter this year?
Class 1, Grade 4 went boating. They rented some boats. If there are four people in each boat, there will be six more. If there are five people on each boat, there will be four empty seats. How many students and how many boats are there? 3 1. A workshop needs to complete a batch of parts. If each group completes 16 pieces, it will exceed 9 pieces. If each group completes 15 pieces, it will exceed 2 pieces. How many teams are there in this workshop? How many parts are there in this batch?
32. The whole class is arranged in several rows. If there are 14 people in each row, there will be 6 people missing. If there are 17 people in each row, there will be less 15 people. How many rows are there in this class? 33. The distance between A and B is kilometers. At 8 o'clock in the morning, the bus travels from A to B, with an average speed of 60 kilometers per hour. The truck travels from B to A at an average speed of 50 kilometers per hour. What time must the truck leave in the morning so that the two cars meet at the midpoint of the journey?
35. Fill in the nine numbers 1-9 to form an equation, and each number can only be used once. □□□×□□=□□×□□=
The average score of these six children in the math exam is 92.5. Their scores are different integers, with the highest score of 99 and the lowest score of 76. Then, according to the score from high to low, how many points does the third-ranked classmate get at least? 39. The product of the sum of the remainder is divided by 7. What is the remainder?
On Children's Day, Xiao Xin's family went to the movies together. Tickets are 4 yuan for adults and 2 yuan for children. Tickets cost 14 yuan. How many adults and children are there in Xiao Xin's family?
42. What is the product of × 37× 27×? (Simplified calculation)
45. Two hours after Xiao Ming came out from his grandfather's house, his father came out from his home 24 kilometers away to meet Xiao Ming. After 2.25 hours, if Xiao Ming came back from his grandfather's house two hours later and picked him up again, 1.75 hours later, what was the speed of Xiao Ming and his father?
46. Xiao Qiang and Liang Xiao discussed that they would leave home at 8 o'clock on Thursday morning. Think about it. Xiao Qiang walks 48 meters per minute, and Liang Xiao walks 54 meters per minute. They met at the midpoint of 30 meters. How long is the road between their two families? In the video game "Defending Home", two guards patrol the 20-meter-long road in front of Lele's house every day. The big guard walks 0.5 meters per second and the small guard walks 0.3 meters per second. Every morning, two people walk to each other from both ends of the two roads at the same time, go to the starting point of each other and then go back. How many meters did the guard walk when they met for the second time?
49. Two cars, A and B, set off from AB at the same time, heading in opposite directions, and meet at a distance of 42km. After meeting, they continue to drive to BA, immediately return at the original speed, and meet at a distance of 30km. How long is the road between AB?
52. Party A, Party B and Party C are all college students. Party A walks 50 meters per minute, Party B walks 60 meters per minute and Party C walks 70 meters per minute. One day, A and B went to the classroom from the dormitory, just as C returned to the dormitory from the classroom, and C met A after 1 minute. How long is the road between the classroom and the dormitory?
Every Sunday, Xiaoming and his parents go to see his grandfather. He walked 60 meters per minute when he went there and 40 meters per minute when he came back. What is their average speed back and forth?
Xiao Ming was sitting on the bus and saw his sister walking in the opposite direction. After 90 seconds, Xiao Ming got off and chased her. If his speed is 1 times faster than his sister's and the speed of the bus is five times that of Xiaoming's walking, how long will it take Xiaoming to catch up with her sister?
55. Zhang is walking on a highway. A bus is coming. He asked the bus driver, "Is there a cyclist behind you?" The driver said, "I overtook a bike 20 minutes ago." Zhang calculated that if the speed of a bicycle is four times that of a human, he will meet a cyclist after walking for another 30 minutes. How many times does Zhang think that the speed of the car is the speed of his walking?
56. Beibei, a Jingba dog, races with baby Persian cat. Beibei's distance of 3 steps is equal to the baby's distance of 5 steps. Beibei runs 4 steps, the baby runs 7 steps and the baby runs to the finish line. How many steps does Beibei need to run to reach the finish line?
58. The road between Xiaoming and Liang Xiaojia is 100 meters long. If they start from home at the same time and walk in opposite directions, they will meet in 20 minutes. If everyone walks 15 meters per minute on average, this is the distance between the meeting place and the first time. If Xiaoming is fast, how many meters does he walk per minute on average?
59, a square, its side length increased by 4 cm, that is, increased by square cm. What is the original side length of this square?
60, an isosceles right triangle, its hypotenuse is 20 cm long, what is its size?
6 1, four students, A, B, C and D, won the first, second, third and fourth place in the 100-meter race in the school sports meeting respectively. Chen said "A is the second, B is the third", Zhang said "C is the fourth, B is the second", and Li said "D is the second, C is the third", knowing that each is half right, where is C?
63. Four people each said a sentence. The first man said, "I am an honest man." The second man said, "We are all liars." The third man said, "Only one of the four of us is a liar." The fourth man said, "Only two of the four of us are liars. Please make sure what the first person says, what the second person says, what the third person says and what the fourth person says.
Three students of a geological college judge a kind of ore: A judges that it is neither iron nor copper, C judges that it is neither iron nor tin, and C judges that it is not tin, but iron. Laboratory tests prove that one person's judgment is completely correct, one person is only half right, and the other person is completely wrong. So who is right, who is wrong and who is half right?
65. Four people, A, B, C and D, took part in a math contest. After the contest, the four of them predicted the ranking as follows: A: "C first, I third." B: "I am first, Ding is fourth" C: "Ding is second, I am third". Ding did not speak. When the result was finally announced, I found that their prediction was only half right. May I ask the ranking of four people in this competition?
66. One of Wang Chun, Chen Gang and Li Huazhong did something bad. Under the understanding, the three of them said the following words: Chen: "I didn't do it, nor did Li Huagan." Wang: "I didn't, and neither did Chen Gang." Li: I didn't do it and I don't know who did it. "When the teacher asked, I learned that they all told a fact, a lie, and who did something bad?
68. A seventh-grade football match in a middle school stipulates that if you win one game, you will get three points; Draw a game and score a point; If you lose a game, you will get eight points. Among them, the number of draws is the same; If you win, you will have one more game; If you win, you will get several games, and you will get several games.
69. The teacher gave apples to the children in kindergarten. If each child gets 2 apples, there are still 30. If 12 children get 3 apples each, and the rest get 4 apples, then it's over. How many apples are there in a box?
70. According to the regulations of the photo studio, it costs 5.40 yuan to take one photo at a time, and three photos will be given. If you want to print more photos, each photo is 0. 40 yuan. Five years 1 class 20 people took a group photo as a souvenir. Each person wants 1 photo. How much does it cost per person on average?
7 1, children divide candy, if each person divides 8, there is still18 left; If the children of 10 get 7 pills each, and the rest of the children get 10 pills, it's over. How many children are there? How many sweets?
72. Workers in garment factories produce four coats or seven pairs of trousers per person every day, and one coat and one pair of trousers make a suit. At present, 66 workers are producing. How many sets can be produced at most every day?
73.A and B * * have 19 stamps, B and C * * have 13 stamps and A and C * * have 16 stamps. How many stamps does A give C, and the number of stamps for three people is the same?
74. Someone has two items. He misplaced the decimal point of one item and paid the salesman 14.07 yuan. The salesman asked him to pay 43.32 yuan. What's the list price of these two pieces?
76. A, B and C have different amounts of money. A has the most money. He gave B and C some money, which doubled their money. Result b is the most. B gave A and C some money, which tripled the money of A and C respectively. As a result, three people have the same amount of money. If the three of them have 8 1 yuan. How much was the original money for three people?
77. It is known that the sum of four numbers is. If the first number adds 3, the second number subtracts 3, the third number multiplies 3, and the fourth number divides 3, the results are all the same. What are these four numbers?
78. Three students, A, B and C, took part in a competition with hats of different colors and clothes of three different colors. It is known (1) that the colors of hats and clothes are only red, yellow and blue. (2) Party A didn't wear a red hat and Party B didn't wear a yellow hat. (3) The students wearing red hats don't wear blue clothes. The students in hats are dressed in red. What color hats and clothes do Party A, Party B and Party C wear?
79. Zhang Ming, Wang Lan and Yao Na like table tennis, swimming and skating respectively. Zhang Ming doesn't like swimming and skating, and Wang Lan doesn't like swimming. Can you name the sports that everyone likes?
80. A, B, C and D play badminton doubles. It is known that (1) A is younger than B (2) D is older than his two opponents (3) A is older than his companion (4) The age difference between A and B is greater than C and D .. Try to judge who is the companion and tell the order of four people from small to large.
8 1. Of the three bags, one contains two pairs of black socks, one contains two pairs of white socks, and the other contains one pair of black socks and one pair of white socks. Now the labels of the three bags are all wrong. Can you take out a pair of socks from one bag and make sure what socks are in each of the three bags?
82. Car A and car B are 90 kilometers apart and travel in the same direction. The speed of car A is 65 kilometers per hour, and the speed of the car is already 50 kilometers per hour. How many hours will it take for car A to catch up with it?
83. My brother and younger brother study in the same school. My brother walks 60 meters per minute, while my brother walks 40 meters per minute. One day, my brother left home five minutes later. When my younger brother arrives at school, so does my younger brother. How far is their school?
84. On the circular runway of meters, both parties walk and run in the same place at the same time. If they walk in the same direction for 3 minutes and 20 seconds, if they walk back for 40 seconds, it is known that A is faster than B. What are the speeds of A and B respectively?
85. Two cars, A and B, leave from A to B at the same time. A travels 38 kilometers per hour and B travels 34 kilometers per hour. 1 hour later, car a returned to a due to an urgent task. Immediately after arriving at A, it will go to B. When A catches up with B, the two cars just arrive at B. What is the distance between A and B?
86. Two ships, A and B, are on the same river, with a distance of 1000 meters. If the two ships are opposite, they will meet in two hours. If they are in the same direction, A will catch up with B in 16 hours. What is the speed of two ships in still water?
87. Two athletes, A and B, ran a one-meter race on a circular runway with a circumference of meters. They both started at the starting line at the same time. Party A runs meters every minute, and Party B runs meters every minute. When Party A was one lap ahead of Party B, Party B began to accelerate, running 80 meters more per minute, and Party A still ran at the original speed. Who will reach the finish line first?
88. A car and a motorcycle set off from Party A and Party B at the same time, driving in the same direction, with the motorcycle in front at a speed of 28 kilometers per hour and the car behind at a speed of 65 kilometers per hour. Four hours later, the car caught up with the motorcycle. How many kilometers is it between A and B?
89. Party A and Party B run on a track with a circumference of 60 meters, and their respective speeds are constant. Party A runs in minutes. If they go in the same direction from the same place, then after 30 minutes, A catches up with B again and meets B. How many meters does B run per minute?
Mingming and Lingling are classmates and neighbors. They walk together after school in the afternoon. Mingming walked home at a speed of 60 meters per minute. Five minutes later, Lingling walked home from school at a speed of 80 meters per minute. Can Lingling catch up with Mingming in a few minutes after she leaves?
9 1, Party A and Party B run on the runway with a circumference of meters, and the speed of each person remains unchanged. If you go in the opposite direction from the same place and meet each other after 2 minutes, if you go in the same direction from the same place, then after 20 minutes, A catches up with B and meets B, then how many meters do A and B run per minute?
92. There are two trains, one with a length of 20 meters per second and the other with a length of 17 meters per second. The two trains run in the same direction. How many seconds does it take from the first train to the second train and then the two trains leave?
93. At the two ends of a circle with a diameter of meters and a circumference of meters, Party A and Party B set off in the same direction at the riding speed of 6 meters per second and 5 meters per second respectively, and traveled along the circle. /kloc-How many times did Party A chase Party B within 0/hour?
94. The tortoise and the rabbit started the race at the same time. The tortoise crawls at a speed of 30 meters per minute. The rabbit runs 100 meters per minute. After running 10 minutes, the rabbit stops to sleep for one minute. After waking up, he immediately ran at the original speed. How far is it from the finish line when the rabbit catches up with the tortoise?
95. There are five natural numbers with an average of 39. If these five numbers are arranged from small to large, the average of the first three numbers is 27, and the average of the last three numbers is 50. What's the middle number?
96. A car is equipped with four tires and a spare tire. The driver rotates the five tires appropriately, but the driving distance of each tire is the same. The car traveled thousands of meters. How many kilometers did each tire travel on average?
97. The average score of Chinese and Mathematics in the final exam in Zhang Tao is 88. After his foreign language scores were announced, his average score increased by 2 points. What's his foreign language score?
Distribute the task of machining parts to three workers equally. Deal with one first, then one, and C deal with one. This means that the total number left by three people is equal to the number allocated to each person. How many parts did each of the three people leave?
Xiaoming took four Chinese exams, with an average score of 68. He wants to raise the average score to 70 after the next Chinese exam. How many points does Xiao Ming need in the fifth Chinese exam?
Choose three numbers from the six numbers of 2.3, 4, 5, 6 and 7 to form a prime number with three different digits, in which the largest prime number is () and the smallest prime number is ().
Seven consecutive natural numbers, each of which is a composite number. Find the minimum value of the sum of these seven numbers?
6cm of water is injected into a rectangular tank with a length of 24cm, a width of 9cm and a height of 10cm, and then a cubic iron block with a length of 6cm is placed. How many centimeters has the water surface risen? There are three cards, write a number 1, 2, 3 on them, draw one, two or three cards from them, and arrange them randomly to get different one, two and three digits. Please write down the prime number?
Is the sum of 1+2+3+4+,,, +49+50 even or odd? There is a square wood with a length of 80cm, which has been sawn into two identical cuboids, and the surface is larger than the original square centimeter. What is the volume of the original cuboid?
Party A, Party B and Party C go to the library to borrow books. Party A comes every six days, Party B comes every eight days and Party C comes every nine days. If we meet in the library on March 5, when will we go to the library next time?
Garden workers planted a tree every 4 meters on both sides of a highway and planted 74 lessons. Now it's time to plant a tree every 6 meters. So, how many don't need transplantation?
Uncle Zhang spent the whole day buying fruit. When counting money at night, he found that the stack of banknotes in his hand was some two-yuan and five-yuan banknotes. Uncle Zhang divided the pile of money into two piles. In the first pile, the number of five yuan and two yuan is equal, and in the second pile, the number of five yuan and two yuan is equal. Do you know how much money there is at least?
Xiaoming wants to put 24 identical cubes into a cuboid. If he wants to put it in the smallest cuboid, how can he put it? (How many pieces are long, how many pieces are wide and how many pieces are high)
Xiao Ming wanted to measure the volume of an iron ball, so he put it in a cuboid container with a length of 20 cm and a width of 15 cm. The iron ball was submerged and the water surface rose by 4 cm. What is the volume of this iron ball?
There is a cube with a side length of 3 meters, which has been sawed twice from top to bottom, twice from front to back and twice from left to right. It happens to be 27 small cubes with a side length of 1 decimeter. How many square decimetres have all the small watches increased? (The loss at the incision is not included)
Dig a small hole with a side length of 1 decimeter in the center of six faces of a cube with a side length of 3 decimeters. What is the surface area and volume of the cube after digging?
Cut off the four corners of a rectangular iron sheet with a length of 20 cm and a width of 16 cm, and then form a cuboid without a cover. What is the maximum volume of this cuboid iron box? (centimeters at seams are not counted)
Cut a cuboid with a length of cm into three sections on average, and the watch will increase by 60 square centimeters. What is the volume of each section?
Liang Xiao has 48 cubes with the same side length of 1 cm. He wants to make a cuboid. He also wants to make the cuboid the largest of all cuboids. What is a cuboid table?
Divide a rectangular block with a length of 5 decimeters, a width of 4 decimeters and a height of 3 decimeters into cubes with a side length of 1 decimeter. How many square centimeters does the sum of all cubes increase compared with the original rectangular table?
Zhang is going to dig a hole with a side length of 1.5 decimeter and a depth of 1 decimeter in the middle of six faces of a cube with a side length of 4 decimeters. After digging, how many square decimeters is the cube's watch? How many cubic meters is the volume?
A cube-shaped part is 30cm long, 20cm wide and15cm high. Make a hole in this part from top to bottom. This hole is a rectangle, 5 cm long and 4 cm wide. What is the volume and table of this part?
Cut a cube with a length of10cm from a cuboid with a length of 60cm, a width of 30cm and a height of 20cm. What is the largest size of the table among the remaining materials? What is the smallest?
Miss Zhao is going to make a water tank without a cover with a rectangular iron plate. Now he cuts a square with the same side length and a whole centimeter from each corner of the iron plate, and then folds it into a rectangular water tank. What is the side length of the square to maximize the volume of the water tank? What is the volume? (The iron plate is 80 cm long and 60 cm wide) Continue to do the problem, and only one student got it right.
The sum of two different natural numbers is 60, and the sum of their greatest common divisor and least common multiple is also 60. How many groups of such natural numbers are there? If the sum of two numbers is 99 and the product of these two numbers is, what are these two numbers?
The product of two adjacent natural numbers is, what are these two numbers?