Solve more Olympiad problems Grades 5 and 6, question answers, the more the merrier, at least two s

1 Female workers in a factory accounted for 1 5 of the total number of factory workers, and later 20 female workers were transferred, and at this time female workers were 1 2 of the number of male workers, then there are now workers ( ) in the factory.

There was no change in the number of male workers, and the number of male workers was considered as unit 1

It turned out that the female workers were male workers.

Male workers have. 20 (1 2 1 4) 80 people.

Now there are female workers.

80 1 2 40 people.

There are now workers in the factory.

80 40 120 people.

2 On the circular runway with a circumference of 400 meters, there are two points, A and B, which are 100 meters apart. A starts from point A and B runs in the opposite direction at the same time from point B [that is, A runs while B runs]. As soon as the two meet, B turns around and runs in the same direction as A, and B arrives at B when A runs to A.

When A catches up with B, A counts how many meters he has run from the start.

Let's say the first point of their encounter is C

According to the inscription, A traveled 400 meters from the departure to return to point A, and B traveled two BC

When A and B met for the first time, A did AC and B did BC

So AC=400*1 2=200 meters, BC=400-100-200=100 meters.

That is, when line A is 200 meters, line B is 100 meters, and more rows: 100 meters.

The second time, A chased B from A, and the difference between the two was 300 meters.

Then when A catches up with B, it should be done: 300 100*200=600 meters.

In addition, A traveled 400 meters in a week, so A traveled a total of 400 meters from the beginning to catch up with B: 600 + 400 = 1000 meters.

Let the original number of female workers be x and the number of male workers be y.

x+20=y/2

x/y=1/4

Solution: x=20

y=80 Now there are 20+20+80=120 in the factory

1) The new tea shop is transported to a batch of first-class tea and second-class tea, of which the number of second-grade tea is one-half of the first-class tea. The purchase price of first-class tea is yuan, and the purchase price of second-grade tea is 16 yuan. Now according to the purchase price increase**, when the second-level tea group leaves are all bought, and the first-class tea leaves are left one-third (3 1), a total profit of 460 yuan, so how many kilograms of first-class tea are transported in?

At least one and the best two: one equation and one equation).

16x (1+RMB).

18-16 = 2 (yuan).

Yuan) Yuan) Solution: The first-grade tea that is transported in is x kilograms.

2x+6x+

x=75 2) A and B cars set off from AB respectively, and went in the same direction. At the time of departure, the speed ratio of A and B is 5 to 4, and after meeting, A's speed decreases by 20% and B's speed increases by 20%, so that when A reaches B, B is still 10 kilometers away from A, so how many kilometers are AB and B apart? (One will do).

A: B = 5:4

Full process: 5+4=9 (portions).

A: B = 5x (1-20%): 4x (1 + 20%) =: 6 When A arrives at place B, B is still from place A

5-4/5x6=1/5

Per serving: 10 1 5 = 50 (km).

Full journey: 50x(5+4)=450 (km).

1 question: (1) Master plan parts: 1600 (1 25%) = 1280 (pieces) (2) Apprentice plan parts:

1280 8 5 = 800 (pcs) (3) Actual parts of the apprentice: 800 6% = 48 (pcs) 2 questions: (1) The score of workshop B completed:

1 40%) 7 5) 7 = 35% (2) Completion rate of workshop C: (1 40%) 7 5) 5 = 25% (3) Total parts: 240 (40% 25%) = 1600 (pieces) 3 questions:

Finding the variable as an invariant).

1) Original: A accounts for 7 10 of the two teams, B accounts for 3 10 of the two teams;

2) Later: A accounts for 3 5 of the two teams, and B accounts for 2 5 of the two teams. ......The reason for the change in the score of A and B is these 20 people.

3) The total number of two teams: 20 (7 10 3 5) = 200 (people) or: 20 (2 5 3 10) = 200 (people) 4 questions: (based on the invariant "science and technology book").

1) The number of science and technology books: 960 8 15 = 512 (books) (2) The total number of later books: 512 16 (15 16) = 992 (books) (3) A few more literary books were bought: 992 960 = 32 (books).

1. The master actually processed 1600, more than 25% of the assigned tasks, so the original task of the master was 1600 (1+.

Therefore, the apprentice's original task was 1280*5 8=800, and the apprentice actually processed 800*.

2. Because workshop A processes 40% of the total number, the number of units processed by workshop B and workshop C is 60% of the total number

And because the ratio of the number of processed units in workshop B and workshop C is 7:5, workshop C processes 60% of the total number * (5 12) = 25%.

Workshop A processes 40%-25%=15% more of the total than workshop C, corresponding to 240 parts.

So there are a total of 240 parts in the batch.

3. The original number of team A was 7 10 of the total number, and now it is 3 5 of the total number, a decrease of 7 10-3 5 = 1 10

And this is caused by the transfer of 20 people from Team A, so the total number is 20.

Team A originally had 200*7 10=140 people, and Team A had 60 people.

4. The original science and technology books in the library were 960*8 15=512, and there were 448 literary and artistic books, and now there are 512*15 16=480 literary and artistic books.

That is, 480-448 = 32 literary books were bought.

1. A batch of parts, originally planned to be processed by the master and apprentice at 8:5, the master actually processed 1600, more than 25% of the assigned task, and the apprentice only completed 6% of the task, how many did the apprentice actually process?

Master's Task: 1600 (1+25%)=1280 (pcs).

Apprentice's quest: 1280 8x5=800 (pcs).

Actual processing of apprentices: 800x6%=48 (pieces).

2. A, B and C three workshops jointly process a batch of parts, workshop A processes 40% of the total number, the ratio of the number of parts processed by workshop B and workshop C is 7:5, workshop A processes 240 more parts than workshop C, how many parts are there in total?

Processing in workshop B and workshop C: 1-40%=60%.

C workshop processing: 60%x5 (7+5)=25%.

Workshop A processes more than workshop C: 40%-25%=15%.

Workshop A has 240 more parts than workshop C.

There are a total of 240 15% = 1600 parts

3. The ratio of the number of people in the two engineering teams is 7:3, if 20 people are sent from team A to team B, the ratio of the number of people is 3:2.

The total number of people remains the same:

A: B = 7:3

A: B = 3:2 = 6:4

Per serving: 20 (7-6) = 20 (person).

The two engineering teams A and B originally shared:

20x(7+3)=200 (person).

4. There are 960 science and technology books and literature books in the library, and the ratio of their books is 8:7, and later some literature and art books were bought, at this time, the ratio of literature and art books to science and technology books is 15:16, and how many literary and art books are bought?

The number of science and technology books remains the same:

Science and technology books: literature and art books = 8:7 = 16:14

Science and Technology Books: Literature and Art Books = 16:15

Per serving: 960 (16+14)=32 (copies).

I bought another literary book: 32x(15-14)=32 (books).

Question 1: Assuming that there are x parts in this batch, then the original plan assigned to the master and apprentice to process is (8 13) * x and (5 13) * x respectively, according to the master excess of 25%, then there is an equation (1 + 25%) * 8 13) * x = 1600, the solution x = 2080, then the actual number of apprentices processed is (5 13) * x * 6% = 48.

Question 2: Assuming that there are x parts in this batch, then workshop A processes 40%*x, workshop B processes (7 12)* 60%*x, and workshop C processes (5 12)* 60%*x, then there is equation 40%*x - 5 12)*60%* x =240, and the solution is x= 1600.

Question 3: Suppose there are x people, then team A has 70%*x people, and team B has 30%*x people, according to the problem of the equation.

70%*x - 20):(30%*x + 20) = 3:2, and the solution equation has x=200

Question 4: From the inscription, before the purchase of books, there are 512 science and technology books, 448 literature and art books, and if you buy x books of literature and art, there is equation 512: (448+x)=16:15, and the solution is x=32, that is, 32 literature and art books are bought.

Note: * means multiplication sign, mainly set unknown series of equations to solve, primary school should be taught.

(1+25%)=1280pcs.

1280 (8 13) = 2080 pcs.

2080*(5 13)=800.

800*6%=48.

2. C processing (1-40%)*5 (7+5)=25%, A is more processing than C, 40%-25%=15%.

The total is 240 15% = 1600

1: 1600 (1+25%)=1280 8+5=13 1280 (8 13)=2080 2080*(5 13)=800.

800*6%=48 Answer: 48 for apprentice processing.

3: Solution: Set up team B x people, team A 7 3x people.

7/3x-20=3/2x

7/3-3/2)x=20

5/6x=20

x=20/(5/6)

x=247/3x=24*(7/3)=56

For the first time, the steamer "Yangtze River" sailed 21 kilometers downstream, and then 4 kilometers against the current. The second time in the same river was 12 km downstream and 7 km against the current, resulting in equal time for both times. What is the speed ratio of a boat going down the river and going against the water?

This problem is solved using complementary methods: 21-12 = 9 (km) 7-4 = 3 (km).

First time, first layer: efgh; 2nd layer: i j k l

abcd mnop

The second time, the first layer is the left half of the second layer of the previous one: j i, the second layer: fe, the third layer: gh, and the fourth layer: kl

nm ba cd op

The third time, the first layer is the previous fourth layer lower part OP, the second layer CD, the third layer BA, and the fourth layer NM

5th layer JI, 6th layer FE, 7th layer GH, 8th layer KL

Fourthly, the first layer is the right half of the eighth layer L, the second layer H, the third layer E, the fourth layer I, the fifth layer M, the sixth layer A, the seventh layer D, the eighth layer P, the ninth layer O, the tenth layer C, the eleventh layer B, the twelfth layer N, the thirteenth layer J, the fourteenth layer F, the fifteenth layer G, and the sixteenth layer K.

Actually, it's a matter of order, I hope it helps you

You should fold it yourself and try it! I've folded it over and it's c!