Answer: Suppose they each donated X books.
( 140-X)=0.8( 170-X)
X=20
2X=40
A: * * * donated 40 copies.
Respondents: soaring 3385- new entrants in the workplace level 3 2009-10-315:19
Reporting solution: (1). Production efficiency w= output/production input, which is equivalent to the number of people.
w =( 1+0.4)/( 1-0.2)= 1.75
(2) Assuming that each person donates X copies, then:
( 140-x)=0.8*( 170-x)，x=20。
Then a ***40 copies.
Responder: Hei Hu's master Gang Ge-Shi Chang, grade 5, 2009- 10-3 15:20.
Report 175%
40 copies
Is he dead?
Is my answer still timely?
If you are not in a hurry.
I'll write another topic analysis and process.
Okay？
After the improvement of production technology, the number of production personnel decreased by 20%, while the output increased by 40%. What is the current production efficiency?
Production personnel are reduced by 20%: that is, it is reduced by 20% on the basis of the original "1"(100%).
Then it is: 100%-20%=80%
But the output has increased by 40%: that is, it is 40% more than the original "1"(100%).
Then it is: 100%+40%= 140%.
Production efficiency = output/personnel
Namely: 140%÷80%= 175%.
All right, next.
Xiaojun has 140 extracurricular books.
Kobayashi has 170 extra-curricular books.
Another example is the book donation in the disaster area.
After they donated the same number of children,
Xiaojun's extracurricular books are Kobayashi 80%, but the ratio of their books now is 8: 10.
4:5
140+ 170=3 10
The closest multiple of 9 and 3 10 is 270=9×30.
Then 3 10-270=40.
All right, all right.
Reply: Crazy Storm-Jianghu Entry Level 4 2009- 10-3 15:29
Solution: 1, assuming that there are X original production personnel, the original output is Y, the original production efficiency is Y/X, and the current production efficiency is (Y+Y*40%)/(X-X*20%), then [(Y+Y * 40%)/(X-X * 20%)
A: The current production efficiency is 175%.
2. Suppose Xiaojun and Kobayashi donated X books respectively, then (140-x)/(170-x) = 80%, and solve the equation X=20, then 2X=2*20=40.
A: Xiaojun and Kobayashi donated 40 extra-curricular books.
Respondent: qltkbd- trainee supervisor level 5 2009- 10-3 15:47.
Reporting naivety! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! 1
Respondent: Dong Shuyu 2009- Magic Apprentice Level 1 2009- 10-3 15:52
Report 40
Respondents: 60. 19 1.8. * 2009- 10-3 16: 30.
Report! Come on! ! ! ! ! ! Come and solve the math problem in primary school! ! I'm dying!
Respondent: LSH 2009 a- Training Supervisor Level 5 2009- 10-3 16:45
Report 175% 40
Responder: Invincible djinn-Senior Chief Sergeant 2009- 10-3 16:58.
Report 2: Assuming that the books donated by each school are X, the formula is:140-x = (170-x) x0.8, which means that X is 20, so * * * donated 40 books.
Answer: Continue to forget you ♀ Star-Intermediate Disciple Level 2 2009- 10-3 17:48.