1. Five puzzles in primary school Olympic mathematics.
There are 1 stamps 10 and 20 *** 18 stamps with a total face value of 2.80 yuan. /kloc-How many stamps are there at 0/0 and 20 respectively? 2. Mother rabbit picks mushrooms. She can pick 16 mushrooms every day in sunny days, and only 1 1 mushrooms every day in rainy days. She picks 195 mushrooms every day, averaging 13 mushrooms every day. How many days has it rained these days? How many sunny days?
3. There are 52 people doing manual work in Class One, Grade Five, three boys and two girls. As we all know, boys do 36 more than girls. How many boys and girls are there in Class One, Grade Five?
The school organized a summer vacation tour. A * * used 10 cars, each bus took 100 people, each bus took 60 people, and the bus took 520 more people than the bus. How many buses are there?
It takes 6 hours and 30 minutes for the plane to fly between two cities with downwind and 7 hours against wind. The known wind speed is 26 kilometers per hour. What is the distance between the two cities?
2. Five questions about elementary school olympiad.
1, Squadron A, Squadron B and Squadron C have 498 books. If Squadron A gives Squadron B four books and Squadron B gives Squadron C 10 books, then the number of books of the three squadrons is equal. How many books does Squadron A have? 2. Xiaohu does a subtraction problem, and writes the six mistakes in the tenth place of the minuend as 9, the nine mistakes in the ninth place of the decimal as 6, and the final difference is 577. What is the correct answer to this question?
Students play the game of throwing sandbags. There are 140 sandbags in Class A and Class B. If Class A gives Class B five sandbags first and Class B gives Class A eight sandbags, then the number of sandbags in the two classes is equal. How many sandbags are there in two classes?
4. When a student does an addition problem, he regards 5 in the unit as 9 and 8 in one tenth as 3, and the result is 123. What is the correct answer?
5. When calculating the addition of two numbers, Xiaowen mistook 1 on one plus several digits as 7, and the other plus 8 on dozens of digits as 3, and the sum obtained was 1946. What is the correct answer to the original addition of two numbers?
6. Xiao Mahu did a subtraction problem, taking 6 in the decimal as 9 and 3 in the decimal as 5, and the result was 2 17. What is the correct answer?
7. Xiaojun was really careless when doing subtraction! Write 3 in the minuend unit as 8 and 0 in the tenth unit as 6, so that the difference he calculated is 199. What is the correct difference?
8. If a number is enlarged by 5 times, subtract 6 to get 39. If you subtract 6 from this number and expand it by 5 times, how much will you get?
9. Add 1 to a certain number, subtract 2, multiply 3, divide 4 to get 9, and find this number.
10, add 6 to a number, multiply 6, subtract 6, divide 6, and the result is equal to 6. Find a number.
3. Five questions of primary school Olympic mathematics intelligence
1, Xiao Gang said: Last year, my father was 4 years older than my mother, and I was 26 years younger than my mother. Please calculate how old Xiaogang's father is this year. 2. Lao Zhang, Amin and Xiaohong are 9 1 years old. Amin is known to be 22 years old, twice as old as Xiaohong. How old is Lao Zhang?
3. The age of the son is 65438+ 0/4 of the age of the father. The sum of the ages of father and son is 49 years old three years ago. How old are father and son now?
My mother is 35 years old, which is exactly seven times her daughter's age. How many years later, the mother is exactly three times the age of her daughter?
Xiaoming is 8 years old this year. The total age of his parents is 8 1 year. How many years later, their average age is 34? How old is Xiaoming at this time?
6. Xiaodong is 12 years old. Five years ago, his grandfather was nine times as old as Xiaodong. How old is his grandfather this year?
7. My mother is 40 years old, just four times as old as Xiaohong. How many years later, mom is twice as old as Xiaohong?
8. There are three people in a family, three of whom are 72 years old. Mom and dad are the same age, and mom is four times older than the children. How old are the three?
9. Grandpa is six times older than Xiaoming this year. In a few years, my grandfather will be five times as old as Xiaoming. In a few years, my grandfather will be four times as old as Xiaoming. How old is my grandfather this year?
10, three years ago, my father was exactly six times as old as my son Xiaogang. This year, my father and son are both 55 years old. How old is Xiaogang this year?
4. Five questions of primary school Olympic mathematics intelligence.
1. I take some apples and pears to the nursing home every day to express my condolences. Take out two pears and four apples from the basket at a time and give them to the old man. Finally, the pear has just been eaten, and there are 27 apples left. At this moment, he remembered that there were three times as many apples as pears. How many apples and pears are there? Answer: (27-3) ÷ (6-4) = 12 (person) 12×2=24 (pear) 24× 3+3 = 75 (apple).
2. When 40 students did three math problems, 25 answered the first problem correctly, 28 answered the second problem correctly, and 365,438+0 answered the third problem correctly. So at least how many people answered three questions correctly?
Answer: The first two questions are correct at least 25+28-40 = 13 (person), and the third questions are correct 13+3 1-40 = 4 (person).
5. Five questions of primary school Olympic mathematics intelligence
1, A and B are 540 kilometers apart. Two cars, A and B, travel back and forth between A and B, and return immediately after arriving at a place. Car B is faster than car A. Suppose two cars start from place A at the same time, and the first and second encounters are on the way to place P, then how many kilometers has car B traveled since the third encounter? Solution: According to the summary, the first meeting, Party A and Party B always * * walked two full distances, and the second meeting, Party A and Party B always * * walked four full distances, and Party B was faster than Party A, and the meeting place was at point P, so it can be inferred from the summary and drawing that from the first meeting to the second meeting, the distance between Party B and the first point P was exactly the first time. So suppose there are three copies of a whole journey. When we meet for the first time, A leaves two copies and B leaves four copies. The second time we met, B just left 1 for B, and came back and left 1. According to the summary, during the two trips, B walked (540 ÷ 3) × 4 = 180 × 4 = 720km, and B walked * * * 720km = 2 160km.
Xiaoming leaves home at 6: 50 every morning and arrives at school at 7: 20. The teacher asked him to arrive at school six minutes early tomorrow. If Xiaoming goes out at 6: 50 tomorrow morning, he must walk 25 meters more than usual every minute according to the teacher's request to get to school on time. How far is Xiaoming's home from school?
Solution: It used to be 30 minutes, but it was 6 minutes earlier, which means it took 24 minutes on the road. At this time, I have to walk 25 meters more per minute, so I always walk 24×25=600 meters more, which is the same as the last 6 minutes of 30 minutes, so I used to walk 600÷6= 100 meters per minute. Total distance =100× 30 = 3000m.