Time: 80 minutes name score

I. Fill in the blanks (6 points × 10=60 points)

1.。

2. There is a series, the first number is 105, and the second number is 85. Starting from the third number, each number is the average of the first two numbers, so the integer part of the number 19 is _ _ _ _ _ _ _.

There are two integers, A and B. The sum of each digit of A is 35, and the sum of each digit of B is 26. When two numbers are added, they are carried three times, so the sum of each digit of A+B is _ _ _ _ _ _ _.

4. In the figure on the right, the radii of three circles are 1cm, 2cm and 3cm respectively, AB and CD are vertical, and the * * passing through these three circles has a center O, and the ratio of the area of the shadow part to the area of the non-shadow part in the figure is _ _ _ _ _ _ _.

5. Natural numbers 1232 1, 90009, 41kloc-0/4 ... have the same characteristics: they are all written backwards or original numbers, so the five-digit even number with this characteristic is _ _ _ _ _ _ _ _.

6. A project can be completed by one person in team A 12 days, and team A can complete half of it in 3 days and 2 days. Now, after a few days of cooperation between Team A and Team B, Team B will do it alone, and it will take _ _ _ _ _ _ _ _ _ days when it is found that the time spent in the two sections is equal.

7. A, B and C run 200 meters. When Party A reaches the finish line, Party B is 20 meters away from the finish line, and Party C is 25 meters away from the finish line. If Party A, Party B and Party C have the same speed, then when Party B reaches the finish line, Party C will be _ _ _ _ meters away from the finish line.

8. Assorted sugar is made of two kinds of sugar, namely 3 parts of A sugar and 2 parts of B sugar, which are more expensive per kilogram than those made of 2 parts of A sugar and 3 parts of B sugar 1.32 yuan, so 1 kg of A sugar is more expensive than that of B sugar 1 yuan.

9. The circumference of a circle is 1.26 meters, and two ants start from both ends of a diameter at the same time and crawl along the circumference. These two ants crawl every second 1 second, 3 seconds, 5 seconds (consecutive odd numbers), and then turn around and crawl. Then, when they met, they had climbed for _ _ _ _ _ seconds.

10. Grade five students in a school 1 10, take part in Chinese, math and English activity groups, and each student should take part in at least one group. 52 people are known to participate in the language group, and 16 people only participate in the language group; 6 1 person participated in the English group, and only 15 people participated in the English group; There are 63 people in the math group, and only 2 1 person in the math group. Then there are _ _ _ _ _ people in all three groups.

Second, solve the problem (10 ×4=40)

1. There are ***780 junior high school students in a middle school. Among the students who go to the Math Art School, there happen to be freshmen and sophomores. So how many junior high school students in this school have not studied in an art school?

2. It is known that the number of students in A school is 40% of that in B school, the number of girls in A school is 30% of that in A school, and the number of boys in B school is 42% of that in B school. Then, what is the percentage of girls in the total number of students in the two schools?

3. The charging standard for electricity consumption in a residential area is: the monthly electricity consumption of each household does not exceed 10 kwh, and the charge per kwh is 0.45 yuan; The part exceeding 10 degree but not exceeding 20 degree will be charged 0.80 yuan per degree; For the part exceeding 20 degrees, 1.50 yuan will be charged for each degree. In a certain month, user A pays 7. 10 yuan more than user B, and user B pays 3.75 yuan more than user C. How much do users A, B and C each pay for electricity? (The electricity fee is charged by the whole degree)

Xiao Zhang, Xiao Wang and Xiao Li set out from the same place by the lake at the same time and walked around the lake. Xiao Zhang's speed is 5.4 kilometers per hour and Xiao Wang's speed is 4.2 kilometers per hour. They are going in the same direction, and Xiao Li is going in the opposite direction. Xiao Zhang and Xiao Li will meet in half an hour, and Xiao Li and Xiao Wang Wu will meet in minutes. So how many kilometers is the journey around the lake?

(5) Reference answer

fill (up) a vacancy

1. 10

Original formula.

2.9 1

According to the topic conditions

The third number

The fourth number

The fifth number

The sixth number

The seventh number

Starting from the eighth number, any number is between 9 1.25 and 9 1.75, so the integer part of these numbers is 9 1. Then the integer part of the number 19 is also 9 1.

3.34

When two numbers are added, the sum of the digits of the sum is reduced by 9 in each round, so the sum of the digits of A+B is.

4. 1 1:7

shaded area

Non-shaded area =

5.400

The first and last numbers can only be one of 2, 4, 6 and 8, which means there are four possibilities. Like the fourth place, the second place can be 0~9, that is, there are 10 possibilities, and the third place in the middle can also be 0~9, that is, 10 possibilities. According to the principle of multiplication, there are 400 such five-digit even numbers in * *.

6.6 days

Team A completed half in six days, team A completed half in three days, and team B completed half in two days, so team A did as much in three days as team B did in two days, so team B's work efficiency was twice that of team A ... Now team B works twice as long as team A and will complete twice as much workload, so if team A completes all the workload, the working time is (days), and the * * * time is.

(days)

7.

When B runs180m, C runs175m, which means that the difference between running180m is 5m, so it is 200m.

8.6.6

Because of the 1 kg mixed sugar prepared by the first method, the first sugar accounts for 0.6 kg and the second sugar accounts for 0.4kg；; In the 1kg mixed sugar prepared by the second method, there are 0.4 kg of sugar A and 0.6 kg of sugar B, so 0.2 kg of sugar A is more expensive than sugar B 1 ... 32 yuan, so1kg is more expensive in 6.6 yuan.

9.49

They * * * crawl 5.5+3.5 = 9 cm per second, in the first half of 1 second, * * * crawl 9 cm;

After another 3 seconds, it climbed 18 cm in the second half. Conversely/kloc-climbed 63 cm in 0/3 second.

The circumference of a circle is 126 cm, and the circumference of a half circle is 63 cm, so they crawl together.

1+3+5+7+9+1+13 = 49 (seconds)

10.8

Second, solve the problem.

1.389

The minimum common multiple of 17 and 23 is that if it is other common multiples, it will exceed 780, which is inconsistent with the meaning of the question. Therefore, 39 1 students entered the Austrian school, and 389 students did not.

2.

Assuming that the total number of students in school B is 1, then the total number of students in school A is, the number of girls in school A is, the number of girls in school B is, and the percentage of girls in both schools is.

3.24.05 yuan

B pays 3.75 yuan more than C, and 3.75 is not an integer multiple of 0.8, so the electricity consumption of C is less than 10 degrees, and B is greater than 10 degrees (less than 20 degrees). If the power consumption of C and B is set, there are

solve

C electricity consumption and electricity charge (yuan)

The electricity fee paid by Party B is 3. 15+3.75 = 6.90 Yuan, and the electricity fee paid by Party A is 6.09+7. 10 = 14.00 Yuan.

Three households * * * pay electricity 3.15+6.90+14.00 = 24.05 yuan.

4.4.2 km

Xiao Zhang left half an hour after meeting (km/h)

A circle around the lake is (kilometers)