The number of books on the upper shelf is 105 more than that on the lower shelf. After taking 25 books from the upper shelf to the lower shelf, the number of books on the lower shelf is four fifths of that on the upper shelf?

The number of books on the upper shelf is 105 more than that on the lower shelf. After taking 25 books from the upper shelf to the lower shelf, the number of books on the lower shelf is four fifths of that on the upper shelf?

If the upper layer x is set, then the lower layer x-105
4/5*（X-25）=（X-105+25）
So the upper level is x = 300
A is one-half of the sum of the other three numbers, B is one-third of the sum of the other three numbers, C is one-quarter of the sum of the other three numbers, and D is 169
Finding the sum of four numbers
A is one-half of the sum of the other three numbers,
So a is one third of the total,
B is one third of the sum of the other three numbers,
So B is a quarter of the total,
C is a quarter of the sum of the other three numbers,
So C is one fifth of the total,
therefore
The sum of four numbers = 169 △ (1-1 / 3-1 / 4-1 / 5) = 169 ± (13 / 60) = 780
There are two layers on a bookshelf. The number of books on the upper layer is 2.5 times of that on the lower layer. If you put 30 books on the upper layer into the lower layer, there will be as many books on the two layers. How many books are there on the upper and lower layers of the bookshelf?
Suppose the number of books in the lower layer is x, then there are 2.5x books in the upper layer, 2.5x-30 = x + 30 & nbsp; 2.5x-x = 60, & nbsp; & nbsp; 1.5x = 60, x = 40, 2.5 × 40 = 100 books in the upper layer. A: there are 100 books in the upper layer and 40 books in the lower layer
A is one-half of the sum of the other three numbers, B is one-third of the other numbers, C is one-quarter of the other numbers, and D is 260
What are the four numbers of a, B, C and D respectively?
A accounts for 1 / 2 of the total number (1 + 1 / 2) = 1 / 3
B 1 / 3 (1 + 1 / 3) = 1 / 4
C 1 / 4 (1 + 1 / 4) = 1 / 5
Total 260 △ 1-1 / 3-1 / 4-1 / 5 = 260 △ 1-20 / 60-15 / 60-12 / 60 = 1200
A 1200x1 / 3 = 400
B 1200x1 / 4 = 300
C 1200x1 / 5-240
400,300,240,260
In a two-tier bookshelf, the number of books on the upper shelf is 2.5 times that of the lower shelf. If 60 books are taken from the upper shelf and put into the lower shelf, the number of books on the two shelves is equal. How many books were put in the upper shelf?
The original lower level has books: 60 × 2 ^ (2.5-1), = 120 ^ 1.5, = 80 (copies), the original upper level has books: 80 × 2.5 = 200 (copies), a: the original upper level has 200 books
The number a is one-half of the sum of the other three numbers, and the number B is one-third of the sum of the other three numbers
The number a is one-half of the sum of the other three numbers, the number B is one-third of the sum of the other three numbers, and the number C is one-quarter of the sum of the other three numbers
260/[1-1/(2+1)-1/(3+1)-1/(4+1)]
=260/[1-1/3-1/4-1/5]
=260/(13/60)
=1200
The number of books on shelf a is 5 / 8 of that on shelf B. If 21 books are taken from shelf B and put into shelf a, the number of books on the two shelves is the same
(1) The number of books on shelf a is five eighths of that on shelf B. If 21 books are taken from shelf B, the number of books on the two shelves is equal. How many books did shelf B have?
(2) The number of books on shelf a is five eighths of that on shelf B. If 21 books are taken from shelf B and put into shelf a, the number of books on the two shelves is equal. How many books are there in shelf B?
The two are different. Pay attention
(1) The original B bookshelf than a 21
Original B 21 (1-5 / 8) = 56 copies
(2) The original B bookshelf is 21 + 21 = 42 more than a bookshelf
Original B 42 (1-5 / 8) = 112
1. Consider the number of bookshelf a as 5, and the number of bookshelf B as 8, that is, the number of bookshelf B is 3 more than that of bookshelf a, and the formula is 21 ÷ (8-5) × 8 = 56
The sum of the three numbers of a, B, C and D is twice as much as 35 A, which is bigger than 5 B. one third of 5 B is equal to half of C. solving the equation of a, B, C and D in March
Classmate, is your narration wrong? There should be no Ding
XYZ is used for a, B and C respectively
X+Y+Z=35
2X-Y=5
1/3Y=1/2Z
Solve the equations x = 10, y = 15, z = 10
The books on shelf a are five eighths of those on shelf B. If 21 books are taken from shelf B, the books on the two shelves are equal. How many books are there on shelf B?
21÷(1-5/8)=56
A total of 60 trees were planted in a, B, C and D. the number of trees planted in a was one-half of that of three people, the number of trees planted in B was one-third, the number of trees planted in C was one-quarter of that of three people, and the number of trees planted in D was several
A total of 60 trees were planted. The number of trees planted by a is half of that of the other three people, that of B is one third of that of the other three people, and that of C is one fourth of that of the other three people. How many trees should d plant?
I'm too lazy to set it up
The other three planted twice as many trees as a
A + 2 * a = 60 a = 20
In the same way
B + 3 * b = 60, B = 15
C + 4 * C = 60 C = 12
D = 60-a-b-c = 13
Fifteen
8 trees
a+b+c+d=60
a=1/2(b+c+d)
b=1/3*60=20
c=1/4(a+b+d)
D=8
The number of trees planted by a is half of that of the other three, indicating that the number of trees planted by a accounts for 1 / 3 of the total
So a 1 / 3 * 60 = 20 trees
The number of trees planted by B is one third of the rest, which indicates that the number of trees planted by B accounts for 1 / 4 of the total
So B 1 / 4 * 60 = 15 trees
The number of trees planted by C is one fourth of that of the other three, indicating that C accounts for one fifth of the total
So C 1 / 5 * 60 = 12
So Ding 60-20-15-12 = 13... Expand
The number of trees planted by a is half of that of the other three, indicating that the number of trees planted by a accounts for 1 / 3 of the total
So a 1 / 3 * 60 = 20 trees
The number of trees planted by B is one third of the rest, which indicates that the number of trees planted by B accounts for 1 / 4 of the total
So B 1 / 4 * 60 = 15 trees
The number of trees planted by C is one fourth of that of the other three, indicating that C accounts for one fifth of the total
So C 1 / 5 * 60 = 12
So Ding 60-20-15-12 = 13 trees, put them away
15ke