2. Form an I-shape with four rectangles of the same size, as shown in the figure below. It is known that the circumference of this figure is 63cm, and the width of each rectangle is long. Then the area of this graph is _ _ _ _ _ cm2.
3. let xyz be a three-digit number with x > z, and if ABC = XYZ-ZYX, then ABC+CBA = _ _ _ _ _ _ _
There is a clock that strikes the hour. It is known that it takes 12 seconds to knock six times at six o'clock, so it takes seconds to knock nine times at nine o'clock.
5. There is an integer. Divide its single digits to get a new integer, and this new integer happens to be the original number, so this number has _ _ _ _ _ _ _ _.
6. There is an infinitely elongated cowhide tendon, and a small ant crawls at a speed of 0.5cm per second at a certain point A of the cowhide tendon. Since the ants began to crawl, the cowhide tendon suddenly stretched twice every 2 seconds, that is, the ants crawled for 2 seconds first, then the cowhide tendon stretched again, and so on. Then, after 1 1 sec, the ant is _ _ _ _ away from point A.
7. A farm has materials to build a fence 100 meters long ... It is planned to build a row of 7 barns, as shown in the figure below. Maximize the use of the built barn area, and the area of each barn can reach _ _ _ _ _ _ _ m2.
8. When Xiao Ming plays a number guessing game in Wenquxing, he has to guess a four-digit number. The result of the previous guess is as follows: The guessed number indicates that 9876 1A0B has 1 bit and the position is correct, and the 0 bit is correct but the position is wrong. 54320A3B has 0 numbers with correct positions, and 3 numbers with correct positions. 9374 1A2B has the number 1 and the position is correct, and two numbers are correct but the position is wrong. 3475 1A2B has 1 number and the position is right, and there are two numbers but the position is wrong. According to these known information, can you help Xiao Ming guess this number? The four digits to guess are _ _ _ _ _ _ _.
9. When the speed of car A is 60 km/h and the speed of car B is 36 km/h, car A and car B respectively start from car A and car B at the same time and meet after 2 hours and 40 minutes. If two cars, A and B, meet at the midpoint of A and B, the second car will leave from B _ _ _ _ _ minutes earlier than the first car.
10. The regular hexagon shown in the figure below consists of 24 small equilateral triangles with a side length of 1. There are _ _ _ _ _ _ * triangles whose three sides are not 1 among the triangles whose vertices are the grid and whose areas are equal to the shaded parts.
1 1. Known exercise books are 0.40 yuan each and pencils are 0.32 yuan each. The teacher asked Xiaohu to buy some exercise books and pencils, and the total price was just given by the teacher 10 yuan. But Tiger confused the number of exercise books with the number of pencils, and got back 0.56 yuan, so the teacher originally planned to let Tiger buy _ _ _ _ _ exercise books.
12. There is an east-west tunnel. Measure the tunnel length, a from east to west, draw a mark (including the starting point) every 7 meters, and b from west to east, draw a mark (including the starting point) every 9 meters. Among all these markers, the distance between the nearest two markers is 0.5 meters, and the minimum distance of several markers like this is 3 1, so the tunnel is at least _ _ _ _ _ meters long.