There are 160 fairy tale books in the school reading room, 1 / 5 less than popular science books. How many popular science books are there in the school reading room?

A: there are 200 popular science books in the reading room

Whether the National Library of China has a study room is whether you can bring books in

No, before entering the building, you should deposit all your things, including your books and drinks, in the bag office on the first floor
Only transparent plastic bags can be brought in. If you take a laptop, you need to get a special bag there

The students planted 126 trees on the hillside in the fourth and fifth grades. The number of trees planted in the fifth grade was twice that of the fourth grade,

If x trees are planted in the fourth grade, 2x trees are planted in the fifth grade
X+2X=126
3X=126
X=126÷3
X=42
A: 42 trees were planted in the fourth grade

What is the integral part of the square root of 2006

√1936= √44²

）The number a is 1.2 times the average of the numbers a, B and C. if the sum of the numbers B and C is 99, what is the number a?

Suppose that the sum of a, B and C is unit 1, then a is 1.2 * 1 / 3 = 2 / 5
1-2 / 5 = 3 / 5
The sum of three numbers is 99 / (3 / 5) = 165
The number of a is 165-99 = 66

We define the operation a & B = a + B / 2 - AB if 1

The results are as follows
one

The sum of a and B is 16.5, the decimal point of a moves one place to the right, which is exactly equal to B. how many are a and B? Explain the formula,
The description is complete

The decimal point of number a moves one place to the right, which is exactly equal to number B
Move 1 bit to the right and enlarge 10 times
The number of B is 10 times that of A
A = 16.5 / (10 + 1) = 1.5
B = 1.5 * 10 = 15

Take any two numbers a and B in the interval [- 2,2], then the probability of two real numbers of quadratic equation x ^ 2 + [2 radical (a ^ 2 + B ^ 2)] x + 1 = 0 is zero______ .

If Δ = 4 (a ^ 2 + B ^ 2) - 4 ≥ 0, then a ^ 2 + B ^ 2 ≥ 1
Let any two numbers a and B obey uniform distribution in the region a ∈ [- 2,2], B ∈ [- 2,2]
The probability of two real numbers is: (4 * 4-3.14 * 1 * 1) / (4 * 4) = 0.80375

There are several milliliters of water in each of the three cups of a, B and C. now pour the water in cup a into cup B to double the water in cup B. then pour one milliliter of water into cup B
Put the water in cup C to double the water in cup C; pour some water in cup C into cup a to double the water in cup C; pour some water in cup C into cup a to double the water in cup A. if you go through the above process, there will be 640 milliliters of water in each of the three cups. How many milliliters of water in each of the three cups?
Each of the three cups contains several milliliters of water. Now pour the water in cup a into cup B to double the water in cup B. then pour some water in cup B into cup C to double the water in cup C. pour some water in cup C into cup a to double the water in cup C. pour some water in cup C into cup a to double the water in cup C. pour some water in cup C into cup a to double the water in cup a If the process is repeated, then there are 640 ml of water in each of the three cups. How many ml of water are there in each of the three cups?

A 880, B 560, C 480

Let a be a matrix of order n and B be a non-zero matrix of order n. if every column vector of B is the solution of a system of homogeneous linear equations AX = 0, what is | a | equal to

Because a (B1, B2... BN) = 0
Get R (a) + R (b) 0 get R (a)

There are 160 fairy tale books in the school reading room, 1 / 5 less than popular science books. How many popular science books are there in the school reading room?