[Archive!] Pure mathematics, physics, chemistry, etc.: brain-training problems not related to trade in any way - page 408
You are missing trading opportunities:
- Free trading apps
- Over 8,000 signals for copying
- Economic news for exploring financial markets
Registration
Log in
You agree to website policy and terms of use
If you do not have an account, please register
You're stubborn. Everyone holds his own score.
As for the Sorento, it's none of my business, but his entry is from the heart. You have to be able to appreciate it.
Further. I appreciate the subtle humor, but sometimes I can't catch up with the dynamics. I can be a little rude.
As for the guy, I don't feel sorry for him. I don't know why he got there. Occupational hazard.
But there was some kind of a favorable outcome. His case.
As far as points of contact, there's two. The fifth point and the rope. The action is, how shall I put it, impulsive.
It's a pity about the bull. The beast is innocently suffering. Don't press the green in the top row at the moment of repulsion, don't mock the animal.
And please don't increase your weight on the landing. You don't have enough bulls.
You've got to be able to keep the skaters healthy at all the high points.
The bull's obviously not a meat breed. He's about a pound or so.
On the second option, the cowboy is obviously patient. Overdrive, that's an article.
I'll say goodbye now - business.
there was a situation... three men had lunch... They brought the bill = 25 roubles, they paid 10 roubles each for lunch... there was 5 roubles in change...
how do you divide 5 by three... So the waiter came over and gave them each a rouble and took 2 roubles for his tea...
So each of the diners got one rouble back, which meant that they spent nine roubles instead of ten.
The question is where did the 1 rouble go... because the meal cost 9 roubles each = 3*9=27, and 2 roubles were taken by the waiter... 27+2=29...and they paid 30
Good day.
At one forum I had a discussion with local experts on the validity of Victor Schauberg's theory. Briefly his postulate, the vortex (turbulent) flow, well as the one that rotates when you open the cork in the bath, has additional kinetic energy compared to laminar flow. The question is whether an experiment should be performed to prove or disprove the VS.
there was a situation... three men had lunch... They brought the bill = 25 roubles, they paid 10 roubles each for lunch... there was 5 rubles left over...
how do you divide 5 by three... So the waiter came over and gave them each a rouble and took 2 roubles for his tea...
So, each of the diners got 1 rouble back, i.e. they spent 9 roubles instead of 10.
You have to ask where the 1 ruble went... because the cost of the meal was 9 roubles = 3*9=27, and 2 roubles were taken by the waiter... 27+2=29...and they paid 30
What the waiter took for himself should be deducted from 27, not added, so:
lunch cost 9 roubles each = 3*9=27, and 2 roubles were taken by the waiter... 27-2=25... went to the feeding and drinking establishment itself
there was a situation... three men had lunch... They brought the bill = 25 roubles, they paid 10 roubles each for lunch... there was 5 roubles in change...
how do you divide 5 by three... So the waiter came over, gave them each a rouble and took 2 roubles for the tea...
So, each of the diners got 1 rouble back, i.e. they spent 9 roubles instead of 10.
The question is where did 1 ruble go... because the lunch cost 9 rubles each = 3*9=27, and the waiter took 2 roubles.. 27+ 2=29... and we paid 30
30 for the place - 3 change for the men = 27 for the place - 2 for the waiter = 25 for the place
bill = payment - tip
payment = bill + tip
tip = payment - bill
We had our lights cut tonight. What's there to do by candlelight? I decided to pick up my logic book to identify my "gaps" in this much-needed discipline. And I found it! Alas, the zadacha I encountered, decided so quickly could not. After a couple of dozen minutes I managed to exclude 2 redundant judgements just by using truth tables (I didn't make formulaic conversions - it contradicts the condition of the problem). Exclude is excluded, but the remaining 2 pairs are somehow not related to each other. I don't understand something here...
Here's the thing. I often have to run some code fragments through logical formulas to reduce the number of lines and increase performance. Well, it's nice when the code is compact and therefore written nicely. Well, when you write a nice code you should always make a full list of all the key events which just form the main branching tree of the program's algorithm. If the code is simple, you may easily keep this tree in mind. If the code is complex, you have to draw it. When drawing a tree, a complete list of events is a must! But often, when compiling a complex algorithm, the list of key events that we compile is redundant. That is, it needs to be reduced to a size where we can safely say that the list of events is complete and sufficient (that is, there is nothing unnecessary and nothing missing). Well, that's the problem I encountered today. It turns out that I simply cannot do it according to formulas of logic, because formulas of relations between complex notions come into play here, and I never paid proper attention to this topic. Anyway, I bring this very problem to your attention - it is worth it!
// -------------------- The problem's condition --------------------------
Below are six statements. Expressing them symbolically and constructing truth tables, choose from them a complete system of alternatives containing four statements:
1) It is snowing but there is no wind;
2) it is snowing if and only if the wind is blowing;
3) it is not true that it snows and the wind blows;
4) it does not snow and there is no wind;
5) it is not true that it snows or there is no wind;
6) it is snowing and the wind is blowing;
// ----------------------------------------------------------------
Hint: A complete system of alternatives is a complex judgement whose molecules are joined together by a string of strict disjunction. The atoms of these molecules can be linked together by any ligament allowed in symbolic logic. In other words - any admissible bundles are allowed inside the molecule, but the molecules themselves are connected only by strict disjunction.
Help for those who don't know: A disjunction is a judgement that offers us a list of possible solutions. They are linked by the conjunction "or". For example "We decided to go to the cinema (A) or have ice cream (B)". It is written in symbolic form "A or B" This judgement will be true in three cases - when at least 1 of the elements is true, and false in one case - when both elements are false. A strict disjunction is an "exclusive or". Elements of this disjunction cannot be simultaneously true or simultaneously false. Here only some 1 is true and the others are false. The truth of this one precludes all the others from being true. For example, in the judgement "a traffic light signal can be red, yellow or green" the conjunction "or" has the meaning of "exclusive or", because the presence of one of these signals automatically rules out the presence of any other, the complete absence of all or the complete presence of all.
Someone may say, "What is the point of solving such problems? For such a person I would say, that believe my experience, programming complicated things is much easier, if you have before you a template from here such already solved problems, or just being able to reduce a complex description of the algorithm to formulas of logic, reducing them (transformations) by the laws of logic.
This is supposed to be a combination of formula truths:
A | B | C | D
1 | 0 | 0 | 0
0 | 1 | 0 | 0
0 | 0 | 1 | 0
0 | 0 | 0 | 1
Man, it's so easy. GOT IT FIGURED OUT!!!! :)
TASK #1:
-
There is a vessel - a flask made of glass. The vessel is sealed tightly with a cork. Inside the vessel there is air and 1.5 kg of flies.
Question: What do the flies have to do to make the vessel lose weight and fly off.
-
PS:
1. The vessel is sealed tightly with a cork. The cork must not be removed from the vessel;
2. The pressure in the vessel is normal, 760 mmHg, and the temperature is 20o C;
3. The conditions outside the vessel are normal - 760 mmHg, temperature - 20gC, acceleration of free fall - 9.81 m\s^2;
4. The vessel has only one opening - with a cork, there are no other openings;
5. The mass of the vessel with a cork and air, but without flies is 1 kg.
It's already flying if g=9.81 m/s^2