Arithmetic problem

First of all, the answer is from the internet, but I have also thought about it and verified it. It took more than two hours.

Question 3: Answer: I climbed 4 meters in 4 days, but it didn't sink on the fifth day, so it took 5 days (or 5 days and 4 nights).

Question 4: Answer: Generally, you can only eat 14 peaches, which is more than the average 15 peaches (first buy 10 peaches, then replace them with 3 peaches+1 peach pit, then replace them with 1 peach pit, and borrow 650 from the boss after eating.

Question 5: Answer: Group number: A: 1234b: 5678c: 9, 10,1,12 Let different balls be X.

The first AvsB

1, equal weight, then x is in c, then take 123vs9, 10, 1 1.

(1), then x= 12. Then 1vs 12 can tell the weight.

(2)123 > 9,10,1.Then 9vs 10, when the weights are equal, x= 1 1 or x= light ball.

(3) 123 & lt； 9, 10, 1 1. Similarly, 9vs 10, equal weight x= 1 1 or x= heavy ball.

2. A>b and Qu 123456789 were divided into three groups,123,456,789.

The second name is 456vs789.

When 456=789, then x= 123 is a heavy ball. Then 1vs2 gets x.

456 >789, 4 or 78 light. After 7vs8, you have X.

456 & lt789 789,56 light. The other 5vs6 has an X.

3, A<b, three groups with 2 points. 123,456,789。

456vs789

When 456=789, 123 is light, and 1vs2 has x.

456 >789 hours weight 56, 5vs6 gain X.

456 & lt789, 4 light or 78 heavy. 7vs8 has an X.

Question 6: Answer: Analysis: Maximize (1000 carrots) when transporting goods, and minimize (1 carrot) when returning, that is, 1 kilometer every time, so (1) when the number of carrots exceeds 2,000, it should be transported three times per kilometer.

(1) 1000/5=200.200 km, the loss is 200*5= 1000, leaving 2000.

(2) When 1000/3 = 333.3, the loss is 333*3=999, and the remaining 1005438+0.

(3) The remaining 100 1 carrot is 1000-200-333=467 kilometers, but only 1000 carrots can be loaded, so it can be sold at last1000-467 = 567.

Question 7: Answer: Let (A- 1)*4/5=A and get A=-4, then there are at least five 6-4 = 1562 1 coconuts. The landlord can verify it himself.

Question 8: Answer: The people in Nakajima are the breakthrough. You just have to ask the Nakajima people, "Is what Oshima people say true?" Then the islanders must answer "yes". The reason is that Oshima people tell the truth, and Nakajima people must also tell the truth, so you ask him, "Is Oshima people telling the truth?" When he has to answer yes. But if the Oshima people lie, so will the Nakajima people. His answer is still "yes". From this, it can be judged which watch the Nakajima people must hold. Now, if you are right-handed, ask the islanders: "Are the islanders sure to raise their right-handed watches?" You can test whether what the islanders say is true or not, and then ask him if what the islanders say is true. We can get the truth of the Nakajima people, and then we can know the truth of the Oshima people, and we can infer where the treasure is. So a * * * four questions 1 asked Oshima: "Is the treasure on the mountain (below the mountain)?" 2. Ask Nakajima: "Is what Oshima people say true?" 3. Ask Kojima: "Are the islanders sure about taking the watch?" 4. Ask Kojima: "Is what Nakajima people say true?"

Question 9: Answer: If there are n * * * in total, then N+ 1 must be a multiple of 3,5,7,9, and the least common multiple of 3,5,7,9 is 3 15, then n+1= 315n. . . Natural number)

According to the meaning of the question, N= 1 1m (m= 1, 2,3. . . . Natural number)

So it is11m+1= 315n.

It is ok to do experiments with a calculator ~ ~ but I also eliminate a rule ~ ~

What is n in 3 15n?

This is logical reasoning. N that makes the above formula effective is 8, 19, 30, 4 1, and so on.

N = 8t+3 (t-1) (t =1.2.3.4 ... natural number)

So 315 {8t+3 (t-1)} =1m+1expansion bracket 3465t-946 =11m (.

So the total number of people n = 3465 t-946.

The total number of people may be 2519 5948 944912914. ...........

10 Question: Answer: First, let's assume that the price of a knife is 5 yuan, and the price of a spoon is 5 yuan ... and then how much money he always has will come out. Fork (2 1*5)+ spoon (2 1*5) will get * * 2 10 yuan. 2 10/28=7.5 yuan. This is the unit price of the knife ... here comes the question ... how many sets of tableware can we buy ... we can buy X sets of tableware. So what's the total price of a set? Knife+spoon+fork. (5+5+7.5)= 17.5 yuan. This is a set of prices. Taking the total price of 2 10/(5+5+7.5)= 12 sets, the final result is 12 sets. You can also introduce other numbers yourself.

1 1 Question: Answer: I'll give you some more answers.

Answer 1: The river was so shallow that the thief waded directly through it. Because you didn't say the depth of the river, you only said 12 meter long.

Answer 2: There is a bridge on the river, and the thief ran over it (you didn't say whether there was a bridge).

Answer 3: A boat stopped on the river and the thief scratched it (you didn't say whether there was a boat).

Answer 4: The thief was actually Phelps, and swam straight over (you didn't say whether the thief could swim).

Answer 5: There is an axe beside the tree. The thief cut the book and let it cross the river (you didn't say whether there was an axe).

Answer 6: The thief tore the scarf vertically into three sections, so that three six meters tied together are twelve meters, then threw it on the other side and tried to tie it, and then waded across the river.

Answer 7 ...

Do you want me to continue?

Ok, since you are all fixed thinking patterns, I will reason the answer according to the given conditions. First of all, the first hint is that all the leaves of the tree have fallen off. The second tip is that the thief is wearing a scarf. What does this mean? It means it was cold at that time. It's winter! So, the answer is simple. The river froze and the thief ran straight over the ice.

I hope my answer is helpful to you.