What are Maths for? The boneiest subject in school programming has a lot of applications, and most of our everyday objects exist thanks to algebra, trigonometry or geometry. And, although we are not going to dedicate ourselves to engineering, the truth is that knowing mathematics makes life easier for us in actions such as carrying out basic banking transactions or keeping track of the family economy.
In this video, the popularizer Miguel Ángel Sabadell explains to us through two very simple examples how mathematics is at the base of almost everything. They are pure anecdotes, but they really show us that maths are not just numbers and letters in a textbook, but that they are very present in the real world.
Scams
Imagine that you have some money saved and you decide to invest it in the stock market, buying shares of company X. The next day you receive a letter from a consultancy that tells you that your shares are going to go down and, indeed, that same day they go down. And so on up to six consecutive times. After this, you receive a letter from the consultant that tells you that, from now on, if you want to continue receiving predictions about your actions, you will have to pay 600 euros.
Would you pay for them? If so, you will most likely fall into the trap. Imagine you have a population of 32,000 people with stocks. You divide them into two groups of 16,000 people: half you send a letter saying that the shares are going to go down, and the other half that they are going to go up. The next day, depending on whether the shares have risen or fallen, you keep the group with which you hit (16,000 people) and again, to 8,000 you will send a letter saying that the shares are going to rise and the other 8,000 that they are going to go down. So on, so that at the end you will have a group of 500 people who have received the correct predictions. If they all bite, the scammer receives 300,000 euros clean.
Probability
Imagine that you have three boxes, and in one of them a check for one million euros is inserted. What is the best strategy to try to hit the correct box? When we choose one of the three boxes, we have a third of the chances of being right, and two-thirds of being wrong.
Imagine that we have chosen the red box, and first the gray box is uncovered, which is empty. Now the options are red box or yellow box. Do we still prefer the red one or do we change our mind? Which is the best option? We have opened the gray box, which is empty, but remember that the gray and yellow boxes, together, had a two-thirds chance of containing the prize, so now the yellow box also has a two-thirds chance of being the winner.
As Miguel Ángel Sabadell explains, mathematics can help you not be ripped off, and also to win in TV contests!
