There are 400 science and technology books and literature and art books. The ratio of science and technology books to Literature and art books is 5:8. How many science and technology books are there?

There are 400 science and technology books and literature and art books. The ratio of science and technology books to Literature and art books is 5:8. How many science and technology books are there?

There are 400x5 (5 + 8) science and technology books. There is a problem with this question, and the proportion is not right. There is not half a book or a fraction of a book

There are 400 literature and art books in the library. The ratio of science and technology books to Literature and art books is five to eight

There are 250 science and technology books

The number of story books in the school library accounts for 25% of the total number of books. The ratio of literature and art books to science and technology books is 7:8. The number of story books is 240 less than that of science and technology books
How many books does the school have?

1-25%=75%
Science and technology books: 75% × 8 / 15 = 2 / 5
2/5-25%=15%
240 △ 15% = 1600 (this)
Answer: the school has 1600 books

3388 is 24 points

8÷(3-8÷3)=24

Function image translation law
The rule of image translation is as follows
(1) : along the x-axis:
(2) : along the y-axis direction:
(3) The translation law is reflected in the analytical formula

(1) For example, y = 2x-5, y = 2 (x + 4) - 5, y = 3x ^ 2 + 4x-2, y = 3x ^ 2 + 4x-2, y = 3x ^ 2 + 4x-2, y = 2x-5, y = 2x-5, y = 2x-5, y = 2x ^ 2 + 4x-2, y = 2X ^ 2 + 4x-2, y = 2x ^ 2 + 4x-2, y = 2x ^ 2 + 4x-2, y = 2x ^ 2 + 4x-2, y = 2x-5, y = 2x ^ 2 + 4x

The bottom area of a cuboid is 20 square decimeters, and the perimeter of the bottom surface is 18 decimeters

Bottom length + width = 18 / 2 = 9
The area is 20
Length = 5, width = 4
Volume = 5 * 4 * 10 = 200 cubic decimeter
Surface area = 2 (5 * 4 + 5 * 10 + 4 * 10) = 220 square decimeters

Use 2,3,4,6 to calculate 24 points (three kinds)

4*6*(3-2) = 24
3*(4+6-2)=24
3*4 + 2*6 = 24

If the particle m moves in a straight line according to the law s = 4T ^ 2 + 1, then the instantaneous velocity of the particle m at t = 2S is (how to do it with derivative)

S is a function of T, the two sides of the derivative s' = 8t, t = 2, s' = 16, that is, the speed is 16. You can think, s is a function of T, that is, s is about the change of T, then the rate of change (that is s') represents the speed

What is the theoretical weight of local standard and national standard of 3mm thick checkered plate?

Diamond 25.6kg/m2, lentil 24.4kg/m2, round 24.3kg/m2

The area of a rectangle is 5 square meters, and the length and width are prime numbers. The perimeter of the rectangle is______

1 is not a prime and has no solution