There are two layers of books on the shelf, a total of 144. If you take out eight books from the lower layer and put them on the upper layer, the number of books on the two layers will be the same. How many books are there on the upper and lower layers of the shelf?

There are two layers of books on the shelf, a total of 144. If you take out eight books from the lower layer and put them on the upper layer, the number of books on the two layers will be the same. How many books are there on the upper and lower layers of the shelf?

The original number of books on the lower level: (144 + 8 × 2) △ 2, = (144 + 16) △ 2, = 160 △ 2, = 80 (Books), the original number of books on the upper level: 144-80 = 64 (Books), answer: there are 64 books on the upper level and 80 books on the lower level
To process a batch of parts, it takes 15 hours for worker a, 20 hours for worker B, and 10 hours for worker C. now, Party A and Party B process for 5 hours at the same time
Don't use equations
To process a batch of parts, workers a need 15 hours, workers B need 20 hours, and workers C need 10 hours. Now, workers a and B need to process 5 hours at the same time, and then workers C need to do it alone. How many more hours
It takes 20 days for workshop a and 30 days for workshop B to process a batch of garments. The two workshops have done it for 5 days at the same time. Workshop a has made 120 sets more than workshop B. how many sets of garments are these
（1-5*（1/15+1/20））/(1/10）=25/6
B and C make 1 / 10 parts per hour
So t = {1 - (1 / 15 + 1 / 20) × 5} / (1 / 10) = 25 / 6 hours = 4 hours and 10 minutes
2. 1 / 20 per day for Party A and 1 / 30 per day for Party B
The total number of garments s = 120 (5 / 20-5 / 30) = 1440
There are three bookshelves in the school library. The first bookshelf is 4 / 5 of the second bookshelf and 1 / 3 of the third bookshelf. It is known that the third bookshelf has 180 books,
How many books are on the first shelf? How many on the second shelf?
Ben is the first of 60;
The second is 75
Almost miscalculated. Hee hee
Workers in a factory process a batch of parts for Chang'e-1 satellite. The original plan is to process 30 parts a day, which will be completed in 8 days. In fact, 120 parts have been finished in 3 days. At this speed, how many days will it take to complete the task? (in proportion)
It will take X days to complete the task
（30×8-120）：x=120 ：3
120 ：x=120 :3
X=3
It will take X days to complete the task. The speed is constant, and the workload is in direct proportion to the working time
（30*8-120）：x=120:3
120:x=120:3
X=3
A: it will take three days to complete the task.
It takes X days
30*8=120/3*x
240=40x
X = 6 days
It will take 6-3 = 3 days to complete the task
There are more than 60 books on the two shelves of a and B. 1?
2. There are 60 more books on bookshelf a than bookshelf B. It is known that the books on bookshelf a account for 60% of the total number of books on the two bookshelves. How many books are there in the two bookshelves? 3. There are 300 books on bookshelf A and B. the books on bookshelf B are 2 / 3 of bookshelf A. how many books are there on bookshelf a? 4. There are 180 books on bookshelf A and 2 / 3 of bookshelf a How many more books are there on bookshelf a than bookshelf B? 5. There are 60 more books on bookshelf a than bookshelf B. the number of books on bookshelf B is 2 / 3 of bookshelf A. how many books are there on bookshelf a? 6. There are 180 books on bookshelf a. the number of books on bookshelf B is 2 / 3 of bookshelf A. how many books are there on two bookshelves?
If the answer is good, don't use the equation, use the formula
1. Book A: 300 * 60% = 180 Book B: 300-180 = 120 Book A is more than book B 180-120 = 60
2. If a accounts for 60% of the total number and a is 60% more than B, then the total number = 60 / 20% = 300
3. If B is 2 / 3 of a, a = 300 * 3 / 5 = 180
4. If 180 * 2 / 3 = 120, 180-120 = 60
5.60/（1/3）=180
6.180*2/3=120 120+180=300
Solution 1: 300 × (60 ‰ - 40 ‰) = 60 copies, 60 copies more for a than B
2: Take the total number of two books as unit 1
60% in a, 40% in B, 20% more in a than in B
The total number is: 60 ﹣ 20 ﹣ 300 copies
3: A: B = 3: 2, the total number is 5
A: 2 = 3 / 5300 × 3 / 5 = 120 copies
4: A more than B: 180 × (1-2 / 3) = 60 copies
5: A: B = 3:2, the total number is 5,
A: 3
Solution 1: 300 × (60 ‰ - 40 ‰) = 60 copies, 60 copies more for a than B
2: Take the total number of two books as unit 1
60% in a, 40% in B, 20% more in a than in B
The total number is: 60 ﹣ 20 ﹣ 300 copies
3: A: B = 3: 2, the total number is 5
A: 2 = 3 / 5300 × 3 / 5 = 120 copies
4: A more than B: 180 × (1-2 / 3) = 60 copies
5: A: B = 3:2, the total number is 5,
A: 3 / 5, B: 2 / 5
The total number is: 60 (3 / 5-2 / 5) = 300 copies
A: 300 × 3 / 5 = 180 copies
6: 180 × (1 + 2 / 3) = 300 copies
There are 300 books to put away
Santa Fe SA
A, B and C process 104 parts at the same time. If the same number of parts are known, B will take 15 minutes,
How many parts are processed by each of the 13 people?
For the same number of parts, it takes 10 minutes for Party A, 15 minutes for Party B and 20 minutes for Party C
Let the same number be a
A 60 min processing 60A / 10 = 6A
B 60 minutes processing 60A / 15 = 4A
C 60 min 60 A / 20 = 3A
So at the same time, the ratio of the number of three people processing is 6:4:3
Let C process 3x, a process 6x, B process 4x
3x+6x+4x=13x=104
X=8
So a processed 6 * 8 = 48, B processed 4 * 8 = 32, C processed 3 * 8 = 24
There are 300 books on the two bookshelves. The number of books on the bookshelf a accounts for 60% of the total. How many more books are on the bookshelf a than on the bookshelf B?
300×60%=180
300-180=120
180-120 = 60 copies
There are 300 × 60% = 180 books on shelf a
There are 300 - 180 books on shelf B = 120
There are 180-120 more books in bookshelf a than bookshelf B = 60
A, B and C process 400 parts in the same time. For each part, B takes 15 minutes and C takes 18 minutes. How many parts should each of them process?
Speed ratio 1 / 10:1 / 15:1 / 18 = 9:6:5
The ratio of quantity is 9:6:5
A 400 △ (9 + 6 + 5) x9 = 180
B 180x6 / 9 = 120
C = 1809 / 100
What is the formula?
There are 300 books in a and B bookshelves. The number of books in a bookshelf accounts for 60% of the total. How many books are there in B bookshelf?
300 × (1-60%) = 120 copies
A, B, C and D work together to process a batch of parts. The number of parts processed by a is 2 / 13 of those processed by the other three people, B is 1 / 4 of those processed by the other three people, and C is one of them
Four out of eleven of the remaining three people, Ding processed 60, and how many of the other three people processed each,
The number of a processing is four of the total number:
2/13÷（1+2/13）=2/15
The total number of people processed by Party B is four
1/4÷（1+1/4）=1/5
The total number of c-processing is 4
4/11÷（1+4/11）=4/15
The total number of processing is four people
1-2/15-1/5-4/15=2/5
Total number of four:
60 △ 2 / 5 = 150 (pieces)
The number of pieces processed by Party A:
150 × 2 / 15 = 20
Number of processed products by Party B:
150 × 1 / 5 = 30
The number of C processing:
150 × 4 / 15 = 40
A total of 60 ÷ [1-2 / (2 + 13) - 1 / (1 + 4) - 4 / (4 + 11)]
=60÷【1-2/15-1/5-4/15】
=60÷2/5
=150
A 150 × 2 / (2 + 13) = 150 × 2 / 15 = 20
B 150 × 1 / (1 + 4) = 150 × 1 / 5 = 30
C 150 × 4 / (4 + 11) = 150 × 4 / 15 = 40
According to the meaning of the title "a processed 2 / 13 of the other three", that is, a made 2 copies, and the other 3 made 13 copies. The total number of copies was 15. A made 2 / 15 of the total. Similarly, B made 1 / 5 of the total, C made 4 / 15 of the total. The total number was regarded as unit "1", and the unit "1" was unknown. The number of these parts could be calculated by dividing the number 60 by the corresponding score rate (1-2 / 15-1 / 5-4 / 15) According to this, we can solve it
　　60÷（1-2/13-1/5-4/15）
=60÷0.4