Superintelligence problems, including high school math knowledge

1.Can't tell unless the first opening is successful.

2. The probability is 5 18

If there are 3 keys, the probability of the first key opening is 1 3, and the remaining 2 keys are 1 2 with the probability of opening the same door with the second key

Therefore, the probability of opening a door with two lockpicks is 1 3 + 1 2 = 5 6.

And the probability of having gold and silver jewelry in this door is 1 3, and the probability of unlocking the lock of gold and silver jewelry is 5 6 * 1 3 = 5 18

1) The first time: 1, use A to open the armor, if successful.

A: Use B to open B, if successful, then C to open C Result: A to open A, B to open B, C to open C.

B: Use B to open B, if it fails, then B opens C Result: A opens A, C opens B, B opens C.

The second time: 2, open the armor with a, if it fails.

C, use B to open B, if successful. Result: A opens C, B opens B, C opens A.

d, use b to open b, if it fails, it is impossible to distinguish.

2) Use three keys to open a specific one lock, two chances.

There are two scenarios.

The first type: the first time to open.

Open for the second time.

s=1/3+1/3=2/3

1. Be able to distinguish.

2, upstairs is not right, the probability of opening a door with the first key is 1 3, the probability of opening the door with the second key is 2 3, and the probability of opening the door with the third key is 1. And the probability of having gold and silver jewelry in this door is 1 3, so the probability of opening the lock lock is 2 3 times 1 3 equals 2 9 for two unlocking opportunities.

1. It can be distinguished, 2. The probability is 5 18

The probability of opening a door with the first key is 1 3, and the probability of opening the same door with the second key is 1 2

That is, the probability of being able to open a door twice is 1 3 + 1 2, which is 5 6. And the probability of having gold and silver jewelry in this door is 1 3, so the probability of these two actions multiplied is 5 18

(1) Calculation.

1 cos(atan(root(99)))2(2) calculation.

141 1232 * 5+6 * root number (14)).

The first one: It seems to be a bit of a problem, and it should be dangerous.

Second, the area becomes smaller and the circumference remains the same.

Thirdly, the radius is r, then the perimeter is 2r plus r, answer 3.

Fourth, the minimum angle is 46 degrees, then the maximum angle must be less than 90 degrees, which is derived from the triangle inner angle and 180.

So it's an acute triangle.

1. Wrong, dangerous.

2.1 Correct.

Three, 3 correct.

Fourth, acute angles.

1.Wade through shallow water.

2. 1.The area has changed, but the perimeter has not changed.

3. 3.πr+2r

4.Acute triangle.

There was a river, and on one side, there were 3 wolves and 3 sheep. Now I want to put them [a lot of them!] They are all transported across the river by boat, and only 2 animals can sit on a boat, and the requirements are: there must be more or equal sheep than wolves on each side, otherwise they will be eaten.

How? Two wolves first, one wolf back.

Two more wolves, one wolf back.

Two more sheep, one wolf and one sheep back.

Two more sheep, one wolf, two more wolves, one wolf.

Finally two wolves.

Xiao Ming and Xiao Hua bought 10 catties of honey and put it in a large bottle. To divide the honey equally, there are only two empty bottles, one for exactly 7 catties and the other for exactly 3 catties. How can honey be separated in the easiest way?

3 7 10 (bottle).