There are forty-five students in a class who took the final exam. After the results were announced, 10 students got full marks in mathematics, 3 students got full marks in mathematics and Chinese, and 29 students got no full marks in both subjects. So how many people got full marks in Chinese?
3.50 students stand in a row facing the teacher. The teacher asked everyone to press 1, 2,3, ..., 49,50 from left to right. Let the students who are calculated as multiples of 4 back off, and then let the students who are calculated as multiples of 6 back off. Q: How many students are facing the teacher now?
4. At the entertainment party, 100 students won lottery tickets with labels of 1 to 100 respectively. The rules for awarding prizes according to the tag number of lottery tickets are as follows: (1) If the tag number is a multiple of 2, issue 2 pencils; (2) If the tag number is a multiple of 3, 3 pencils will be awarded; (3) The tag number is not only a multiple of 2, but also a multiple of 3 to receive the prize repeatedly; (4) All other labels are awarded to 1 pencil. So how many prize pencils will the Recreation Club prepare for this activity?
5. There is a rope with a length of 180 cm. Make a mark every 3 cm and 4 cm from one end, and then cut it at the marked place. How many ropes were cut?
6. A cylinder with a bottom radius of 1 decimeter has a square profile. What is the surface area and volume of this cylinder?
Analysis: Starting from the square of the side expansion diagram, we can know that the height of this cylinder is the circumference of the bottom of the cylinder.
7. A train leaves from Station A at 8 a.m. and arrives in bilibili at 9 p.m. the next day. As we all know, the train travels at an average speed of 98 kilometers per hour. How long is the railway between Station A and bilibili?
8. The radii of a circle and a sector are equal. It is known that the area of a circle is 30 square centimeters and the central angle of a sector is 72 degrees. Find the area of the sector.
9. The school assigned the task of planting trees to the sixth and fifth grades in a ratio of 5: 3. The sixth grade actually planted 108 trees, exceeding the original task by 20%. How many trees were planned to be planted in the fifth grade?
10, two engineering teams, Party A and Party B, completed a section of highway, and the working efficiency of Team A was 3/5 of that of Team B ... Two teams completed two-thirds of the road in six days, and the rest was repaired by Team B alone. How many days will it take to finish it?
1 1. A cement factory produced 232400 tons of cement last year. The output in the first five months of this year is equal to that in the whole of last year. According to this calculation, the output of this cement plant will increase by a few percent this year compared with last year.
12, the kindergarten bought 40 towels of different sizes, which cost 258.8 yuan. The unit price of a large towel is twice that of a small towel, with a difference of 0. 1 1 yuan. What is the unit price of these two kinds of towels?
13, calculation: 0.02+0.04+0.06+0.08+…+19.94+19.96+19.98 = _ _ _ _ _.
14, 1× 1+2× 2+3× 3+ unit numbers ...1997×1997+1998×1.
15, a two-digit number, add a 0 between its two digits, which is 630 more than the original number. Such two digits are _ _ _ _ _.
16. At present, there are four RMB 1, two RMB 2 and three RMB 10. If you take at least 1 and at most 9 RMB, then * * * can be matched as _ _ _ _ _ _ _.
17, a set of four digits, each digit is not 0, and they are different from each other, but the sum of all digits of each digit is 12. Arrange all the four digits from small to large, and the 25th digit is _ _ _ _ _ _ _ _.
18. The big monkey gives the little monkey peaches. If each monkey gets 8 peaches, there are 10 peaches left. If each little monkey is divided into 9 peaches, then a little monkey will be divided into less than 9 peaches, but it can still be divided into peaches, small ones.
19, there is a residential building, each family subscribes to two different newspapers, and the residential building subscribes to three newspapers. Among them, there are 34 Nantong radio and television newspapers, 30 Yangzi Evening News and 22 newspaper abstracts. Then, Yangzi Evening News and Newspaper Digest have _ _ _ _ _ _ subscribers.
20. Qiang Qiang and Fang Fang are running back and forth in a straight line, with a distance of 120 meters. Qiang Qiang runs 2 meters per second and Fang Fang runs 3 meters per second. If two people start from both ends at the same time, then * * * meets _ _ _ _ times in 15 minutes.
Answer:
1, because both groups 10 participated, so five people only participated in mathematics, and eight people only participated in airplane models. Plus that 10 makes 23 people, and 40-23= 17, 17 both groups did not participate.
2. Similarly, the perfect score in mathematics is 10, and the perfect score in two subjects is 3, so the perfect score in mathematics is only 7, and 45-7-29=9. This is the person with full marks in Chinese (if it is only full marks in Chinese, you need to subtract 3).
3, 50 ÷ 4 is rounded to 12, and 50÷6 is rounded to 8, but it should be noted that the multiple of 4 may be a multiple of 6 at the same time, so the common multiple of 4 and 6 should be calculated, and 50 ÷12 (the least common multiple of 4 and 6) =4 (rounded).
4, 100 ÷ 2 = 50, 100 ÷ 3 = 33 (rounded), or calculate the common multiple of 2 and 3 100÷6= 16 (rounded), and then find out that it cannot be.
5, 180 ÷ 3 = 60, 180 ÷ 4 = 45, but two dashes may be drawn together to calculate their common multiple,180 ÷ 3 ÷ 4 =/kloc-0.
6. Analysis: Starting from the square of the side expansion diagram, we can know that the height of this cylinder is the circumference of the bottom of the cylinder.
Surface area of cylinder:
(3. 14× 1×2)×(3. 14× 1×2)+3. 14× 1× 1×2
=6.28×6.28+6.28
=6.28×7.28
=45.7 184 (square decimeter)
Cylinder volume:
3. 14× 1× 1×(3. 14× 1×2)
=3. 14×6.28
= 19.7438+092 (square decimeter)
A: The surface area of this cylinder is 45.75438+084 square decimeter, and the volume is 19.438+092 square decimeter.
7. Analysis: The key to solve this problem is to know the time of the train.
24-8+9=25 (hours) [or: 12-8+ 12+9=25 (hours)]
98×25=( 100-2)×25
=2500-50
=2450 km
A: The railway between Station A and bilibili is 2450 kilometers long.
8. Analysis: Because the radii of the circle and the sector are equal, the area of the circle and the sector should be multiple. This multiple is the multiple relationship between their central angles.
72÷360= 1/5, 30× 1/5=6 (square centimeter)
The area of this sector is 6 square centimeters.
9. Analysis: The number of trees planned for the sixth grade is the key to solving the problem.
/kloc-How many trees were originally planned to be planted at Grade 0 and Grade 6?
108 ÷ (1+20%) =108× 5/6 = 90 (tree)
2. How many trees were planned to be planted in the fifth grade?
90÷5×3=54 (tree)
Comprehensive formula:
108÷( 1+20%)÷5×3
=90÷5×3
=54 (tree)
A: It was originally planned to plant 54 trees in the fifth grade.
10, Analysis: Finding the working efficiency of two teams is the key to solving the problem.
1. What is the sum of the work efficiency of the two teams?
2/3÷6= 1/9
2. How efficient is Team B?
1/9×[5÷(3+5)]
= 1/9×5/8
=5/72
3. How many days will it take to complete?
( 1-2/3)÷5/72
= 1/3×72/5
=24/5 (days)
A: It will take another 24/5 days to complete.
1 1, the solution 1: The analysis shows that the output in the last seven months of this year is increasing, so we have to calculate the output in the last seven months first.
232400÷5×( 12-5)
=46480×7
=325360 (ton)
325360÷232400= 1、4= 140%
Scheme 2: "1" with the unit of 232,400 tons,
1. Compared with last year, what is the average monthly output this year?
1÷5= 1/5
2. How much has the output increased this year compared with last year?
1/5×( 12-5)=7/5
Compared with last year, what percentage has the output increased this year?
7/5= 1.4= 140%
Comprehensive formula:1÷ 5× (12-5) =1.4 =140%.
The output of this factory this year has increased by 140% compared with last year.
12, Solution: If the unit price of small towel is X yuan, the unit price of large towel is (2x+0. 1 1) yuan.
[x+(2x+0. 1 1)]×40 = 258.8
3x=6.47-0. 1 1
x = 6.36 \3
x=2. 12
2x+0. 1 1 = 2. 12×2+0. 1 1
=4.35
A: The unit price of large towels is 4.35 yuan each, and the unit price of small towels is 2. 12 yuan each.
Those who fill in the blanks behind don't know the answer.