Give you some clever questions in primary school.

1. There are several chickens and rabbits in the cage, which is *** 100 feet. If the chicken is replaced by a rabbit and the rabbit is replaced by a chicken, it will have 92 feet. How many rabbits and chickens are there in the cage?

2. A class of 42 students participated in tree planting, with an average of 3 trees planted by boys and 2 trees planted by girls. As we all know, boys have 56 more trees than girls. How many boys and girls are there?

3. In the following equations containing △, □, ○, △, □, ○, they represent different natural numbers, among which one number is known to be 99, and the largest number in □ is _ _ _ _ _ _ _.

△+□+○=△×□-○

Spiders have eight legs, dragonflies have six legs and two pairs of wings. Cicada has six legs, 1 pair of wings. At present, there are 18 of these three kinds of bugs, with 1 18 legs and 20 pairs of wings. How many bugs are there in each species?

5. Two kinds of food *** 100 Jin, with a total value of several yuan. Now, after the price of A is reduced by 20% and the price of B is increased by 20%, the total value of two kinds of food per kilogram of 9.6 yuan is less 140 yuan. How much is each of these two foods?

6.1.The distance between a and b is 465 kilometers. It takes * * * 7 hours for a car to travel from A to B at a speed of 60km/h and then accelerate to 15km/h to arrive at B. How many hours have you been driving at a speed of 60 km/h?

7. There are 10 playing cards with points of 1, 2, 3, …, 9, 10 respectively. Pick a few cards at will. In order to make the sum of points of some cards equal to 15, how many cards should be taken at least?

8. Take three numbers from the number 0 of 10, 1 2.

9. After a store increased the purchase price of a DVD by 35%, it advertised "10% discount for guests and taxi fare for 50 yuan". As a result, each DVD still earned 208 yuan. What is the purchase price of each DVD?

10. Several cases were unloaded on the freighter, with a total weight of 10 ton, and the weight of each case did not exceed 1 ton. In order to ensure that these boxes can be transported at one time, how many cars with a load of 3 tons are needed at least?

1 1, in the following six □, fill in the six numbers 1, 2, 3, 4, 5 and 6 respectively, so as to minimize (greatly reduce) the difference between the two three digits, and the minimum value is _ _ _ _.

□□□-□□□

12. Palindrome number refers to the number from the first digit to the last digit, which is the same as the number from the last digit to the first digit (for example:111,22222,100/kloc. What is the ratio of the number of five palindromes divisible by 1 1 to the number of all five palindromes? Please use the simplest score to express the answer.

13. After a rope is folded in half for 4 times, cut it into several small pieces with a knife at each of the three dividing points. These little ropes come in two lengths. Among them, how many are longer? How many shorter ones are there?

14. Three students in each class form a team to participate in the relay race, and it is required that three students in the same class are not completely adjacent. How many arrangements are there?

15. Xiaoming went to the store and bought 66 red and black pens. Each red pen is priced at 5 yuan, and each black pen is priced at 9 yuan. Because of the large quantity, the store gave a discount. The red pen paid 85% of the price and the black pen paid 80% of the price. If the price he pays is 18% lower than the price, he will buy it.

. . . . . . . . The answer? I'll give it to you after you adopt it