|
190207 还原机经选题: 数论&代数
|
a,b,c,d are positive one-digit integers. ac+bc+ad+bd=65. |a+b-c-d|=?
|
|
190207
|
If integers between 1 and 238 will be typed with the keyboard, what is the minimum number of times to tap 9?
|
|
190207
|
The radius of the circle O is r. AO is perpendicular to OB. What is the area of the shaded part?
1：∠BAC = 30°
2：∠CAO = 30°
|
|
190215
|
10 ≤ n ≤ 99 . n is an integer which can be divided by both 3 and 7. What is the number of the possible value of n?
|
|
190215
|
The vertex coordinates of quadrilateral ABCD are A (3,1), B (10,1), C (5,8), D (3,5). How many right angles are there in this quadrilateral?
|
|
190215
|
Machine A needs 5 hours to complete a task. When machines A and B work together, the same task can be completed in 1.875 hours. How long does it take for B to finish the task alone?
|
|
191020
|
The triangle ABC is a right-angled triangle, and B is the right angle. If a point D is on AC, is the triangle BCD an isosceles triangle?
(1) BD = AD
(2) D is the midpoint of AC
|
|
191020
|
It is given that a/(a+b)=5，what is the value of b/(a+b)
|
|
191020
|
It is given that: $$T_n$$ = 1 + 2 +3+. . . + n, so is $$T_n$$ an odd number?
1: $$T_{n+1}$$ is odd
2: $$T_{2n}$$ is even
|
|
191020
|
As shown in the figure, a ball will move from point A to point E, so how many different ways to move?
|
|
191020
|
What is the reciprocal of the sum of the reciprocals of 2, 4, 6, and 12 ?
|
|
191020
|
Tom invests A and B with same amount of money x. The rate of return of A and B is 6% and 8%, respectively. What is the total amount of principal?
|
|
191020
|
If x and y are integers, and $$( x - y ) ^ { 2 } + 2 y ^ { 2 } = 27$$ , how many possible values of x?
|
|
191020
|
X^4-X^3+X^2-X>0?
(1)X^4>X^2
(2)X<0
|
|
191020
|
The total cost of 100 products is 189, and 15% of the products are defective and can not be sold. What is the price of the remaining products can make the total profit of 100?
|
|
191020
|
There are less than 50 books. If 7 books are packed into a box, one book will be left. How many books are there?
(1) If 9 books are packed into a box, 7 books will be left
(2) If 4 books are packed into a box, 3 books will be left
|
|
190215
|
Two circles of the same size intersect to form three regions, as shown in Figure 1. How many areas will be formed at most when two squares of the same size intersect?
|
|
190215
|
In rectangular coordinate system, ABC is a right triangle. AC is perpendicular to BC. What is the abscissa of C?
1：A(10,5)
2：B(0.5,2)
|
|
191020
|
If $$x^3=-3$$, which of the following is the value of x2?
|
|
190215
|
The list price is 20% higher than the wholesale price. The retail price is 15% lower than the list price. How many times the wholesale price is the retail price?
|