The three teams of A, B and C build a road, and their work efficiency is different. If you follow th

1.There are 51g and 45g of salt in the two plates of the scale, so how much salt should be taken out of plate A and put in plate B to make them equal in mass?

2.There are a total of 95 students in class A and B, and the average achievement rate in a physical education test is 60%, if the achievement rate of class A is 40%, and the achievement rate of class B is 78%, what is the number of students in class A and B?

3.A project, A alone does 20 hours to complete, B alone to complete 12 hours, now A alone does 4 hours, and the rest is cooperated by A and B, how many hours does it take to complete?

4.A project, team A alone takes 7 days to complete, team B alone takes 5 days to complete, now team A does a day alone, team B joins, ask team B how many days to complete the project?

5.To build a highway, it will be repaired by three engineering teams of A, B and C in sections, engineering team A will repair three-sevenths of the whole process, team B will repair the remaining four-sevenths, and engineering team C will repair 12 kilometers.

6.There are 62 workers in a workshop, producing two kinds of parts A and B, and each person can produce an average of 12 parts A or 23 parts B per day. (A part for every three A parts and two B parts to form a set).

Question addendum: Add another 50 points.

Asked by: A503864289 - Assistant Level 2

1. Let x be the number of grams of salt that should be taken out, 51-x=45+x, and solve x=3;

2. Set x as the number of people in class A x*40%+(95-x)*78%=95*60% Solve x=45 (number of people in class A) 95-45=50 (number of people in class);

3. Let the remaining part of A and B cooperate for x hours: (1 20)*4+(1 20+1 12)*x=1 to solve x=6;

4. Set x days to complete: (1 7) + (1 7 + 1 5) * x=1 solve x=

5. Let the length of the highway be x (1-3 7) * x * (1-4 7) = 12 and solve x = 49

6. The person who produces the first part is x 12x 3=(62-x)*23 2 and solves x=46

Solution: Suppose the first three people use the last day to get A's turn, suppose B does x every day, and C does y every day, then x+1 2y=1 15

then y+1 3 1 15=1 15

y=2/45 x=2/45

But their work efficiency is different, so if they fail, the first last day is B's turn and then suppose B does x every day and C does y every day, then x+y+1 30 = x+1 30 finds y=1 30, y+1 15+1 3x=x+1 15 finds x=1 20

Team B will need to repair 20 days alone, and Team C will need to repair 30 days alone.

9÷[1-40%-(1-40%)x75%]=60

A: The road is 60 kilometers long.

Dizzy, all the masters are here!

First of all, we need to know that the work efficiency of team A is 3 5 of team B, that is. The ratio of the work efficiency of team A to the work efficiency of team B is 3:5, here we regard the work efficiency as the basis of speed, and the formula of speed multiplied by time equals distance is calculated:

3+5)x6=8ⅹ6=48。Then we know that the two teams completed 2 3 of this road in six days, and the equation is obtained: 48 2xl=24, which is the distance that team B will repair alone.

Then, according to the formula of distance divided by speed equals time, we get the equation 24 5 = days).

Hello! We'll be happy to answer your questions.

The combined efficiency of the two teams is: 2 3 6 = 1 9

Team B's efficiency is: 1 9 (1+3 5)=5 72Team A's efficiency is: 5 72 3 5=1 246 days later, the remaining 1 2 3=1 3

Let B be x, A is 3 5x, 6 (x+3 5x) = 2 3, find x, 1 3 divided by x

The amount of work remaining divided by the efficiency of B is the time remaining.

The overall length is: 200 (1-50%-30%)=1000 meters.

Team C repaired: 1000*30%=300 meters.

A bears half of it, C bears 30, because the three families built a road together, so B built 1-1 2-3 10=1 5 Therefore, the total length is 200 1 5 = 1000 meters, so C repaired 1000*3 10=300 meters.

Solution: 1-1 3 2 3 3+5 8 2 3*(3 8) 1 4 Let the total length of the road be x meters, and the equation of the problem column is: 1 3 x = 1 4 x + 24 Solution: x = 288 (m).

A: The total length of the road is 288 meters.

Set the total length of x meters.

Team A = x 3

Team B = (2x 3)*3 (3+5).

Team A - Team B = 24

x/3-x/4=24

x=288

1 3 x = 1 4 x + 24 Solution: x = 288 (m) Answer: The total length of this road is 288 m.

= 1200 (meters), A: The total length of this road is 1200 meters

It takes x days for B to do it alone.

Then B's work efficiency is small.

That's 1 x A is 3 5x

Because the two teams repaired together for 6 days, it was just two of the three traces of this section of the road.

6（1/x+3/5x)=2/3

8/5x=1/9

x=72/5

So B's work efficiency is 5 socks 72

So the number of days needed is 1 3 5 72 = 24 5 days.

24/5 of a day.

Let A be x days, B y days, and C z days, then A completes 1 x per day, B completes 1 y per day, and C completes 1 z per day, (1 x+1 z)*4=1

1/y+1/z=7/9(1/x+1/z)

1 x+1 y=10 7(1 y+1 z) solves the equation system, and obtains x=6 , y=9, z=12 A repairs for two days, B and C repair for 3 days, and the rest of A, B and C cooperate to complete: [1-(1 6)*2-(1 9+1 12)*3] (1 6+1 9+1 12)=3 13 Tianwang.

Efficiency = 2 3 4 = 1 6

A efficiency = 1 6 (1 + 3 5) 3 5 = 1 16

A also = (1-2 3) 1 16 = 16 3 days.

Let the efficiency of B be x, then the efficiency of A is.

Completed a total of 4*(x+) in 4 days of cooperation

then x=5 48 1 16

The remaining time is 1 3 1 16 = 16 3 6 days.