2. (The examination questions are attached to the middle school attached to Tsinghua University) It is known that car A has a speed of 90km and car B has a speed of 60km. Two cars leave from A and B at the same time, and the B car arrives earlier than the A car on the C road 10 minute; The next day, Party A and Party B set out from B and A respectively and returned to the original starting point at the same time. When passing through C, Party A arrived 1.5 hours earlier than Party B, so what is the distance from AB?
3 (Exam 11) The walking speeds of A, B and C are: A walks 90 meters, B walks 75 meters and C walks 60 meters per minute. A and C start from the west end of a long street, and B starts from the east end of the long street, and are opposite at the same time. Just four minutes after A and B met, B and C met. How long is this long street? rice.
4 (Xicheng Experimental Examination) A and B walk back and forth between A and B, and A starts from A and B at the same time; The first meeting point is 60 meters away from B. B came back from A, left 10 meters, and met A for the second time. How many meters are a and b apart?
5 (the exam questions are attached to the First Normal University) A and B are running back and forth on a straight road with a length of 100 meters. The speed of A is 3 meters per second, and the speed of B is 2 meters per second. If they start from both ends of the straight at the same time, how many times will they run 10 minutes * * *?
6 (The examination questions are attached to the middle school attached to Tsinghua University) Cut a cube from a cuboid with a length of 8 cm, a width of 7 cm and a height of 6 cm, and the surface area of the remaining geometry is _ _ _ _ _ _ _ _ square centimeters.
There is a cube with a side length of 1 m. After cutting two knives, three knives and four knives along the length, width and height, it becomes 60 small cuboids. The total surface area of these 60 small cuboids is _ _ _ _ square meters.
8 (Exam attached to Junior High School) A thousand small cubes with a volume of 1 cubic centimeter are combined into a large cube with a side length of 10 cm. After the surface of the big cube is painted, it is divided into the original small cubes. How many of these cubes have at least one side painted?
9 (Examination questions attached to the middle school of Tsinghua University) Large trucks and cars start from the same place and drive along the same highway. The truck drove 1.5 hours first, and the car caught up with the truck four hours later. If the car travels at a speed of 5 kilometers per hour, it will catch up with the big truck in three hours. Q: How many kilometers does this car actually travel per hour?
10 (Xicheng Experimental Examination) It usually takes only 20 minutes for Xiao Qiang to go to school by bike. Because there are 2 kilometers of roads under construction on the way, I have to walk by cart, and the walking speed is only 1/3 by bike. It took me 36 minutes to get to school. How many kilometers is it from Xiao Qiang's home to school?
11(1kloc-0/middle school exam questions) PHS and grandpa started from here at the same time, PHS walked back, and grandpa took the bus in the first 4/7 of the distance, which was 10 times faster than PHS. Grandpa walked back the rest of the way, and his walking speed was only half that of PHS. Please guess who are our grandfathers and grandsons.
12 (sanfan middle school exam) buses and trucks travel in opposite directions from the midpoint of the two cities. Three hours later, the bus arrived in the city, and the truck was 30 kilometers away from the city. As we all know, the speed of a truck is 3/4 that of a bus. How many kilometers are there between the two cities?
Xiaoming runs three times as fast as he walks. He walks from home to school every day. One day, because he left 10 minutes late, he had to run half the distance and walk the other half, which was the same as the time to get to school in peacetime. So how many minutes does Xiao Ming need to walk to school every day?
14 (examination questions attached to the middle school of Tsinghua University) If the eight numbers 14, 30, 33, 35, 39, 75, 143, 169 are divided into two groups on average, so that the products of the two groups are equal, the score will be scored.
What's the status of the group?
15 (three times high school exam) observation1+3 = 4; 4+5=9 ; 9+7= 16 ; 16+9=25 ; 2 25+ 1 1=36, find out the law, and then fill in 200 1 +( )=2002.
16 (Dongcheng No.2 Middle School Examination) is between two numbers. Write 5 for the first time, and write 7 and 8 between 2, 5 and 5 and 3 for the second time (as shown in the figure below). Write the sum of two adjacent numbers between two adjacent numbers that have been written. This process is repeated six times. What is the sum of all the numbers?
Please select some numbers from 0 1, 02, 03, …, 98, 99, so that for any infinite number string consisting of some numbers from 0 to 9, there are two adjacent numbers, and these two numbers are one of those you selected. In order to achieve these goals.
(1) Please specify that the number 1 1 must be selected;
(2) Please specify that at least one of the numbers 37 and 73 should be selected;
(3) Can you choose 55 numbers to meet the requirements?