In this article we will see one of the riddle oldest in the world:
A brick weighs a more half brick kilo. How much does the brick weigh?
Before seeing the solution of this riddle, try to think about it for a moment without using paper and pen. What answer would you give?
The solution of the brick indovinel
If you replied 1.5 kg you have… wrong! It is the most common answer, but it is a deception of your mind that, hearing “a more half brick kilo” immediately thinks about the hamlet of the kilo as part of the solution, but that’s not the case!
We see two ways possible to solve this problem: the first using a simple reasoning, the second by setting amathematical equation who will tell us the solution with certainty.
50% of the weight of the brick
To resolve the riddle without the use of a sheet but only of the reasoning, Let’s analyze the phrase piece by piece: “A brick weighs a more half brick kilo”. If we stop for a moment to think, “half brick “ it is equivalent to considering the 50% of the brick. And a brick from how many parts is formed? By two half, that is, from “two 50%”. This suggests that if a brick is formed by one of his half to which it is added a kilothis kilo will constitute its other half! Well, we discovered that a kilo is equivalent to half of the brick and therefore our brick will weigh .. 2 kg!
Set an equation for brick

If the reasoning above has not convinced you, we use a simple equation to find the solution. We therefore call m Our brick and translate the protagonist of the IndoVinello into mathematician
A brick (m) weigh (=) a kilo (1 kg) more half brick (m/2)
from which we get the formula
m = 1 kg + m/2
Multiplying both members of this equation by 2, we get 2m = 2 kg + m. Now subtracting from both sides m, we get
m = 2 kg