2. Uncle Wang's vegetable field is 800 square meters, ready to grow tomatoes. The rest are planted with cucumber and eggplant according to the area ratio of 2︰ 1. What are the areas of the three vegetables?
Form a rectangle with a 28-meter-long iron wire. The length-width ratio of this rectangle is 5:2. What is the length and width of this rectangle?
4. Form a triangle with 84 cm long iron wire, and the length ratio of three sides of the triangle is 3︰4︰5. How many centimeters are the three sides of this triangle?
5. The ratio of degrees of three internal angles of a triangle is 1︰2︰3. What is the biggest angle in this triangle? What triangle is this triangle?
6. The road team needs to build a 432-meter-long road, which has been repaired. The remaining tasks are divided into two road repair teams according to 5︰4. How many meters do the two road repair teams need to repair?
7. In the activity of "learning from Lei Feng", the students in grade five and grade six did 80 good deeds on average, and the ratio of the number of good deeds in grade five and grade six was 3︰5. How many good deeds did the fifth and sixth grade students do respectively?
8. The distance between the two cities is 225 kilometers. A bus and a truck left two cities relatively at the same time and met after 2.5 hours. As we all know, the speed ratio of trucks and buses is 4: 5. How many kilometers do buses and trucks travel per hour?
9. Weld a 282.6 cm long iron bar into a circular iron ring. What is its radius?
10. For round bottom boilers, the circumference of the bottom circle is 1.57m, and what is the bottom area? (Figures shall be kept to two decimal places)
1 1. Xiaodong has a bike. The diameter of the wheel is about 66 cm. If the average speed is 100 laps per minute, then the distance from home to school is 4 144.8 meters. How many minutes will it take?
12. The minute hand of the wall clock is 20 cm long. After 30 minutes, how many centimeters did the tip of the minute hand walk?
13. The radius of the circular cowshed is 15cm. How long does it take to circle the cowshed three times? (joints are ignored. ) If a stake is installed every 2 meters, how many stakes will be installed?
14. The range of automatic rotary sprinkler irrigation device on the park lawn is 10 meter. How wide can it spray irrigation?
15. The circular roundabout is 50m in diameter, with a circular flower bed with a diameter of10m in the middle and lawns in other places. What is the area of the lawn?
16. A circular flower bed with a perimeter of 3 1.4m is built in the downtown garden, and a circular path with a width of 1m is built around the flower bed. What is the area of this path?
17, Xiaoming bought stamps with 50 cents and 80 cents *** 16, and * * * spent them 10.7 yuan. How many stamps does Xiao Ming buy each?
In 2002, China Academy of Sciences and China Academy of Engineering had a total of 1263 academicians, including male academicians 1 185. What percentage of academicians are women?
19, Team A and Team B dig canals. It takes 8 days for Team A to dig alone, and it takes 12 days for Team B to dig alone. Now, after two teams dug for a few days at the same time, team B was transferred, and the remaining team A finished digging in three days. Bravo team dug for a few days.
There is a two-digit number, and the sum of its digits is 7. If you subtract 27 from this number, the number you get is exactly the reverse order of the number. Find this number.