First, fill in the blanks. (2 points × 10 = 20 points)
1, concentration 19% brine b kg, including salt kg and water kg.
2. If the decimal number 1995xy599 1 is divisible by 99, then x =.
3. The five-digit abcde is a multiple of 9, where abcd is a multiple of 4, so the minimum value of abcde.
Because.
4.m mu of land yields 1 kg of rice per mu, N mu of local rice yields 2 kg, and m+n mu of land yields rice per mu on average.
Kilogram.
5. Deposit one yuan into the bank according to the current demand, with a monthly interest rate of 2.4‰ and a three-month interest rate of RMB.
6, in the prime number of two digits, the maximum sum of two digits is
Second, multiple choice questions. (3 points × 7 = 2 1 minute)
1, there are two numeric strings 1, 3, 5, 7, …, 1997, 1999 and 1, 4, 7, 10, …,/kloc-. a、333 B、334 C、335 D、336
2. The largest integer divisible by the sum of any five consecutive integers is () a, 1 B, 2 C, 3 D, 5.
3, 196 apples, if not all at once, nor one by one, how many apples you need to take each time, there are () ways to take them. a、4 B、6 C、7 D、9
4, a kilogram of salt and b kilograms of water mixed brine concentration is ()
A, a/(a+b) B, a/(a+b)% c, 100× {a/(a+b)}% d, none of the above are correct.
If m people can finish the work in d days, it will take m+r people () days to finish the work.
a、d+r B、d-r C、md/(m+r) D、d/(m+r)
6. If the quotient of a÷b is11+24, then the minimum value of B is ().
A, B, 25, 28, 33 days
7. If the value of algebraic expression 2y2+3y+7 is 2, then the value of algebraic expression 4y2+6y-9 is ().
a、 1 B、- 19 C、-9 D、9
Three. Column algebra formula (3 points× 5 =15 points)
1, the quotient of the number less than 3 divided by the number greater than 5.
2. the difference between a and b is multiplied by the product of a number smaller than the sum of a and b by 3.
3.3 times the sum of x and y divided by the difference between the quotient of x and 3 times y.
4. Quotient of number 5 greater than 0/2 of 65438+X and number 3 less than 2 times of y. ..
X is a two-digit number and y is a three-digit number. Please list the five digits representing xy.
Algebraic expression
Fourth, the calculation problem. (6 points × 5 = 30 points)
1, given that a = 3b and c = a/2, find the value of (a+b+c)/(a+b-c).
2. Given (x-2)2+ 1y-3 1=0, find the value of xx+yy-xy-yx.
3. Given (a-b)/(a+b)=2, find the value of algebraic expression 2(a+b)/(a-b)-(a-b)/3(a+b).
4. Given a+b+c=0, find A (1/b+1/c)+B (1/c+1/a)+C (1/a+/kloc).
5. It is known that positive integers P and Q are prime numbers, and 7p+q and pq+ 1 1 are also prime numbers. Find the value of pq+qp.
Verb (abbreviation of verb) proof problem. (8 +7 = 15)
1, let m = (b-a) (c-d) (d-a) (d-c) (a-b) (c-b), where a, b, c and d are integers, and verify 12/M(8 points).
2. Prove that if the prime number P≥5, 2p- 1 is a prime number, then 4p+5 is a composite number. (7 points)
Sixth, the application problem. (7 points× 3 = 21min)
1. A school has about 400 students in eight classes in grade one. In the process of queuing, there were two more students in the third row, three more students in the third row and seven more students in the seventh row. How many students are there in Grade One? (Find the exact number)
2. The ship runs between A and B, with the speed of m kilometers per hour in still water and the speed of water flow of n kilometers per hour. (1) List the algebraic expression of the average speed of the ship between A and B. ② When m = 15 and n = 2, the average speed is obtained.
3. In order to effectively control the harm of severe weather such as sandstorm to human living environment, a certain place in northern China decided to plant trees at a rate of 40% every year. It is estimated that 30,870 mu of trees will be planted in 2005. How many acres will be planted this year?