Kindergartens buy some books. Science and technology books account for 1 / 3 of picture books and story books, picture books account for 4 / 5 of science and technology books and story books account for 14, How many science books and picture books are there?

Kindergartens buy some books. Science and technology books account for 1 / 3 of picture books and story books, picture books account for 4 / 5 of science and technology books and story books account for 14, How many science books and picture books are there?

Science and technology books account for 2 / 5 of the total books,
Picture books account for 4 / 9 of the total books
Story books account for 1-2 / 5-4 / 9 = 7 / 45
The total number of books is 14 / (7 / 45) = 90
Science and technology book is 90 * (2 / 5) = 36
90 * (4 / 9) = 40 for picture books
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There are 270 pages in a story book. How many pages does Cong Cong read in one ninth of seven days?

270/9=30
30*7=210

It took Congcong three days to finish reading a story book. On the first day and the second day, he read two thirds of the whole book. On the second day and the third day, he read five sixths of the whole book?

On the first day and the second day, I watched 2 / 3, then I watched 1 / 3 on the third day, then I watched 5 / 6 on the second day and the third day, then I watched 1 / 6 on the first day, so I watched it on the second day
1-1/6-1/3=1/2

One fifth of the pages of story books are equal to one fourth of the pages of science and technology books. Comparing the pages of the two books, how many pages of story books are the pages of science and technology books
Come on, it's urgent

Let X be the total page number of story books and a be the total page number of science and technology books
Five story books are bigger than four science and technology books
One fifth of every story book = one fourth of every science book
A is less than x
X-a = one fifth of X
Results page 25 was OK

How many centimeters is 5'10 "in the United States? How many feet and inches is 153 cm?

Using the measurement conversion tool:

Let the variables X, y, Z satisfy the constraint conditions: x + y + Z = 1,0 ≤ x ≤ 1,0 ≤ y ≤ 2,3y + Z ≥ 2, find the maximum value of F = 3x + 6y + 4Z

From the title: z = 1-x-y substituted into 3Y + Z "2: x-2y + 1" 0 ", X and Y belong to the rectangular trapezoid surrounded by, 0 ≤ x ≤ 1,0 ≤ y ≤ 2, x-2y + 1" 0 ", the four vertex coordinates are: (0,1 / 2), (1,1), (1,2), (0,2) substituting z = 1-x-y into F = 3x + 6y + 4Z: F = 2y-x + 4 Let f

English translation
I like to ride a bike on weeks?

At the weekend refers to a specific weekend. For example, a person said a few months ago what he was doing on that weekend. 3. The refers to a specific weekend. At the weekend and on the weekend are the same meaning. Usually at the weekend 4. On weekends refers to a thing to be done on several or more weekends

A number minus 1 can be divided by 2, minus 2 can be divided by 5, minus 3 can be divided by 7, plus 4 can be divided by 9, the minimum number is______ ．

From 63n-4, the number of bits of 63n-4 is 7; the minimum number is 437

Find the partial derivatives α Z / α x, α Z / α y of the implicit function z = f (x, y) determined by the equation x ^ 2 / A ^ 2 + y ^ 2 / b ^ 2 + Z ^ 2 / C ^ 2 = 1

(1 / 4 + 5 / 6-2 / 3) multiply by 12, 24 times 2 / 5 + 75 divide by 2.5 + 0.4, (4 and 7 / 8 + 13 / 16) divide by 13 / 16
Simple calculation

(1 / 4 + 5 / 6-2 / 3) times 12
=1/4*12+5/6*12-2/3*12
=3+10-8
=5
24 times 2 / 5 + 75 divided by 2.5 + 0.4
=24*0.4+75*0.4+0.4*1
=（24+75+1）*0.4
=100*0.4
=40
(4 and 7 / 8 + 13 / 16) divided by 13 / 16
=(4 + 7 / 8 + 13 / 16) * 16 / 13
=39/8*16/13+13/16*16/13
=6+1
=7