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Analysis: First classify and write out the year of the Hua Cup as follows:

1991, 1993, 1995, 1997, 1999, 2001, 2003, 2005, 2007, 2009, 2071, 2073, 2075, 2077, 2079, 2081, 2083, 2085, and then according to the characteristics of the number on each digit

Answer: The years of the Hua Cup are as follows:

Therefore, the 50th Chinese Cup will be held in 2085

a50=43 2+(1+3+5+7+9) 8+5 (1+3+5+7+2+4+6)+3 8+1+3+5+(1+9) 7+2 8+6+8+5 9+(1+3+5+7+9)=629 Wang!!

The 50th Hua Luogeng Gold Cup was held in 2085, so a50 = 2 + 0 + 8 + 5 = 15

Konami's kite.

Divided into 4 triangles.

The area of the 4 triangles is added together.

Half of the graphic area of the whole forest cavity.

So. The area of the small kite is 20x40=800cm 2, because the ratio is 3; 1

Then the area ratio is 9; 1

Therefore, the area of the kite is 800x9=7200cm2

1620 is an even number.

Multiples of even numbers can only be even.

And 25 is an odd number.

426 is an even number.

So a paper with 25 questions must be an even number.

An even multiple of 25 is a multiple of 50.

Note that the single digit of 2050 is zero.

So the single digit of their multiples is also zero.

And the single digit of 426 is 6

And there are only 16 of the three numbers left.

So if there is one or six or sixteen parts of 16 questions (16x1=16, 16x6=96, 16x16=256 digits are all 6)!!

So there are 2x copies of 25 questions.

Y copies of 20 questions.

Just make a binary equation.

Set 25 questions x, 16 y questions, and 20 z questions, so: x+y+z=23, 25x+16y+20z=426, note that the single digit of 426 is 6! 25x single digits: 0 or 5, 16y single digits: 0, 2, 4, 6, and single digits: 0, because the sum of the three single digits = 6! So: 25x single digits = 0, 16y single digits = 6, so the single digits of :x may be: 0,2,4,6, and the single digits may be: 1,6. It's time to eat. Wait a minute!

There are 20 questions x times.

25 questions y times.

The number of times 16 questions may appear is 1 time.

6 times 11 times.

16 times 21 times.

When 16 questions appear 1 time.

x+y=23-1

20x+25y=426-16*1

No solution: when the 16 questions appear 6 times.

x+y=23-6

20x+25y=426-16*6

No solution: when 16 questions appear 11 times.

x+y=23-11

20x+25y=426-16*11

x=10y=2 when 16 questions appear 16 times.

x+y=23-1

20x+25y=426-16*16

No solution, when 16 questions appear 21 times.

x+y=23-1

20x+25y=426-16*21

No solution: To sum up, there are 20 questions, 10 times, 25 questions, and 2 times.

First of all, you have to know that one liter is equal to one cubic decimeter. is the cubic decimeter. According to the conditions, the length and width of the glass container are 2dmThen the water depth at this time should be, then the apple occupies the high water, then the volume of the apple is 2*2*cubic decimeter.

The base area is 2*2=4 square decimeters of the depth of water).

After putting in the apples, the difference is.

This difference is caused by the apple's draining of water, and this part of the volume is the base area multiplied by the height that is 4 * cubic decimeters (l).

After putting in the apples, the volume of water and apples is 2dm*2dm*

Then the volume of the apple is:

cubic centimeter 2dm=20cm

The volume of an apple: v = 15 * 20 * 20 - 5500 = 500 (cubic centimeters).

This problem should be completely submerged in water. First of all, you can calculate that the volume when you put it in is 2*2*; Then the volume of the apple is because 1dm3=1l).

Method 1: H original =

h=v=s*△h=20*20*

Method 2: V end = 2*2*v:

Use a chopstick to pass from one of the cups to the middle of the other two cups, so that the chopsticks are perpendicular to the chopsticks between the two cups, and then cut off the growing part and connect it with the chopsticks, and you can put it on the two cups.

You can cut off two chopsticks from the middle, and then one of the truncated ones stands upright in the center of the three glasses, so that the distance between the three cups and the chopsticks is a quarter of the root number three, about, shorter than the length of half of the chopsticks, so that the remaining three half-length chopsticks can be placed in the middle of the vertical chopsticks and the glass, that is, the requirements of the problem are completed.

Addendum: It is true that the third quarter of the root number three is a false ......, that distance should be three-thirds of the root number, which is ...... largerIf you don't restrict the use of glue, you can do it, but it seems to be a ...... limitMy previous answer was wrong.

Since ed=mn=bc2, and ed bc mn, the quadrilateral ednm is a parallelogram, then the point o is the midpoint of ec and dm, then bo=2mo=2od

co=2no=2oe

The midline on the side of BC must pass the O point, reason:

Connecting AO, the parallel line of CE through point B intersects the extension line of AO at point P, and the extension line connecting CP and AO intersects BC at point Q

Then OE is the median line of the triangle ABP, 2OE=BP, and 2OE=CO, so the quadrilateral BOCP is a parallelogram, and the point Q is the midpoint of BC.

bo=2do, the midline on the edge of bc crosses the o point.

Proof is that if we connect ao, let m and n be the midpoints of bo and co respectively, and connect em and dn respectively, then:

EM parallel and equal to half of AO, DN parallel and equal to half of AO.

So: em is parallel and equal to dn

So: the quadrilateral emnd is a parallelogram.

So: mo=od

So: bm=mo=od

So: bo=2do

Extend AO BC to G, extend DN BC to H, extend EM BC to Q, then:

From ag eq dh, bm=mo=od, bq=qg=gh=hc, so; bg=gc

So; The midline on the side of BC crosses the O point.

Solution: According to the midline theorem, bo do=2;

And the midline on the side of BC also crosses the O point, which is also according to the midline theorem.

bo=2od.Must have passed the O point, and learned that the vector is very good to push. When I didn't study, I memorized theorems.

Solution: Bo=2OD, whether the midline on the edge of BC must pass the point O Reason: As shown in the figure, let M be the midpoint of Bo, N be the midpoint of Og, connect Mn, Em, and DN because the points D and E are the midpoints of AB and AC.

So de is the median line of the triangle.

So de=1 2bcd, de is parallel to bc

In the same way, it can be proved that mn=1 2bcd, mn is parallel to bc, so mn=de, and mn is parallel to de

So the quadrilateral demn is a parallelogram.

So o is the center of the parallelogram demn.

So do=mo

Because m is the midpoint of bo.

So mo=1 2bo

So do=1 2bo

1.The owner of the shop has 1 yuan. Another person is charged 8 yuan, 3 * 8 = 24 + 1 + (1 yuan per person) 3 yuan + 2 yuan for the tip of the second child, a total of 30 yuan.

2.The green onion seller only sold 50 catties of green onions white (scraps) and 50 catties of green onions (scraps), not 100 catties of good whole green onions.

It can be thought that the person who sells green onions has 100 catties of good green onions, 50 catties of green onions white (scraps) and 50 catties of green onions (scraps).

He just sold (scraps) 100 catties, nothing to lose.

If you use good green onions to divide them into green onions and green onions, they should be white green onions and green onions.

Then you won't lose money.

3.5 days.

On the first day, go up 3 meters back to 2 meters and stop at 1 meter.

On the second day, go up 3 meters back to 2 meters and stop at 2 meters.

On the 3rd day, go up 3 meters back to 2 meters and stop at 3 meters.

On the 4th day, go up 3 meters back to 2 meters and stop at 4 meters.

On the 5th day, I went up 3 meters from 4 meters to the well, so why don't you go back?

4.15 pcs.

Eat 10 first, exchange 10 peach pits for 3 peaches and 1 pit left, then exchange back for 1 peach, there is 1 pit left, borrow a pit from the peach seller to make up 3 pits and then exchange 1 peach, and return the pits after eating. 5.

For the first answer, everyone paid 9 yuan, including 2 yuan for the waiter. So when calculating, as long as 3 * 9 = 27, plus 1 yuan returned by each person, 27 + 3 = 30. Just consider it unilaterally.

The second answer is that if you buy green onions alone, it's only 1 yuan a catty. But the green onion white and green onion were sold separately, 7 cents a pound of green onions, 3 cents a pound of green onions, together is 1 yuan and two catties. So** half folded.

The third one is too simple, it can be climbed in 5 days. Climb one meter a day, climb 4 meters for 4 days, and climb 3 meters on the fifth day.

The fourth answer is 14 peaches, eat 10 peaches for one dollar, there are ten hu for three peaches, and the remaining 4 hu for one peach, a total of 14 peaches.

1.Because 29 + 2 = 31, that dollar does not have. 2...3.7 days 4After eating 3 peaches, I had 3 more peaches and 4 peaches.

After eating 3 peaches, I got 3 peaches, and I exchanged 8 peaches for one peach. After eating 3 peaches, I had 3 more peaches for 12 peaches. After eating 3 peaches, I had 3 more peaches and 16 peaches.

There is also a corner to buy a peach 17. 5...