The third grade question is difficult!!

1) There are 100 chickens and rabbits, and there are 80 more chicken feet than rabbit feet, how many chickens and rabbits are there?

The number of chickens more than rabbits: 80 2 = 40 (only).

The number of rabbits: 100-40 = 60 (only).

60 2 = 30 (only).

Number of chickens: 100-30 = 70 (chickens).

A: There are 70 chickens and 30 rabbits.

2) There are 100 chickens and rabbits, and there are 80 more chicken feet than rabbit feet, how many feet do chickens and rabbits have?

The number of chickens more than rabbits: 80 2 = 40 (only).

The number of rabbit's feet:

100-40=60 (only).

60 2 = 30 (only).

30*4=120 (only).

The number of chicken feet: 100-30 = 70 (only).

70*2=140 (only).

How many feet do chickens and rabbits have: 140 + 120 = 260 (only) Answer: Chickens and rabbits have a total of 260 feet.

There are 100 chickens and rabbits, and there are 80 more chicken feet than rabbit feet, how many chickens and rabbits are there?

The number of chickens more than rabbits: 80 2 = 40 (only).

100-40=60 (only), if the number of rabbits is x, then the number of chickens is 2x, (2x chicken feet = x rabbit feet).

So: x + 2x = 60

Number of rabbits: x=20 (only).

The number of chickens: (2x+40)=80 (chickens).

Let's say 100 are all chickens, there should be chicken feet.

2 100 200 pcs.

At this time, there are 0 rabbits and rabbit feet.

4 0 0 only.

There are more chicken feet than rabbit feet.

200 0 200.

More than it actually is. 200 80 120 pcs.

This requires a chicken for a rabbit, 1 chicken for 1 rabbit, and the chicken feet are much less than the rabbit's feet.

4 2 6 only.

Rabbits have. 120 6 20 only.

Chickens have. 100 20 80 pcs.

Solution: If there are x chickens, then rabbits have (100-x).

2x-4(100-x）=80

2x-400+4x=80

6x=480

x=80A: 80 chickens and 20 rabbits.

Set the chicken x rabbit y only to:

x+y=100

2x-2y=80

Solution: x=70

y=30 chickens 70 rabbits.

Could it be that the rabbit has 4 legs haha freak?

Set chicken x rabbit y

2x-4y=80

x+y=100

Solve on it.

For questions like this, if you count from back to front, 25-8=17 is the remaining half of the morning, so there are 34 left in the morning, and 34+12=46 is half of the total, so the total is 92.

This question is really difficult for Bai to become a Du person.

Why? Because we are far away.

Isolated from arithmetic thinking.

It's been so long that we've become accustomed to equation thinking.

I'll try to do it below:

1. Problem solving ideas:

If the remaining 25 minus the 8 that were sold less, that would be half of the remaining afternoon. That is: 25-8 = 17.

Then, the remaining half of the afternoon is 17*2=34;

If the remaining half plus the 12 oversold is half of the total, that is: 34 + 12 = 46.

Then the total number is 46*2 = 92.

2. Calculation. A total of 92, more than 12 were sold in the morning, that is 92 2 + 12 = 58.

92 - 58 = 34 left.

Sell half in the afternoon and lose 8, that is, sell 34 2 -8 = 9 and leave 34 -9 = 25.

To sum up, the answer is 92.

There are ((25-8) 2+12) 2=92 (pcs).

Inspection: Morning Sell 92 2+12=58, remaining 92-58=34.

Afternoon Sell 34 2-8=9 and 34-9=25 remaining.

All left: 33*2=66

Half in the morning: 66 + 12 = 78

All: 78*2=156

Use homework to help you take photos and search for answers.

Zhaozhou Bridge! , three ancient poems, and the invention of paper.

It's an even number. 59 is a prime number because the multiples of 59 are only 1 and itself.

Speed is a matter of ha.

Let the water be 100, then the speed of the duck is 100 divided by 25=4, and the speed of the chicken and duck together is 100 divided by 20=5, then the speed of the chicken is 5-4=1, which takes 100 days.

Hello dear parents and teachers.

If A gives 5 stamps to B, then A and B will have the same number of stamps.

Explain that A has 10 more sheets than B before.

If B gives 5 to A, then A will now have 20 more than B.

B's stamps are only half of A's, A's are 2 times that of B, 1 times more is 20 stamps, B is now 20, and A is 40.

A was originally 40-5 = 35 sheets.

B turns out to be 20 + 5 = 25 sheets.

Set: A has x sheets, then B has x-5 sheets.

x-5-5=1/2x

The solution is x=10

10-5=5 (sheets).

A: A has 10 sheets and B has 5 sheets.

Let A be x stamps and B be y stamps.

If A gives B 5 stamps, then A and B have the same number of stamps, and x-5=y+5 can be deduced from this sentence

If B gives 5 stamps to A, then the stamps are only half of A's, and y-5=(x+5) 2 can be deduced from this sentence

It can be obtained by two formulas, y=25 and x=35

So A originally had 35 stamps, and B had 25 stamps: A had x, then B had x-5.

x-5-5=1/2x

The solution is x=10

10-5=5 (sheets).

A: A has 10 sheets and B has 5 sheets.