Another mathematical puzzle has appeared on the Internet, which haunts people. At first glance, everything is very simple: in the left column, there is a countdown from 9 to 3, in the right column there are numerical matches. We need to fill in the missing.

The task caused serious battles online. Try to solve it yourself!

### Now let’s see what the answers might be.

So, some people found the product of multiplication in the right column. The solution is simple: multiply the number on the left by the same number minus one: x(x−1), which gives the result in the right column. For example, 9(8) = 72, 8(7) = 56, etc. Following this rule, we get the answer 6: 3(2) = 6.

### And that’s everything? No!

Other people have come up with this solution: they have noticed the sequential difference between the numbers in the right column – 72 – 56, then 56 – 42, then 42 – 30, etc., which gives a decreasing difference of 16, then 14, then 12 and etc. Each subsequent number is less than 2. In this case, the last answer should be 12.

### But that’s not all! There is a third solution!

In the left column, you can see the multiplication going down by 1: 9 × 8, then 7 × 7, then 6 × 5, and so on. In this case, the answer is 9, because at the end it will be 3 × 3 = 9.

### But could it be that one of the three solutions is better than the others?

First, let’s look at the sequence in the left column. Each subsequent number is less than the previous one by 1 – except for the last line, which is less by 2. Of course, we can easily calculate that the line with the number 4 is missing.

Why is the missing line so important? And here’s why: if we use any of the three sequences described above to solve – x(x−1), decreasing subtraction, or decreasing multiplication – then when we add a line with 4, we get the same answer in all three options! And that answer is 6.

Therefore, it is logical to assume that the missing line fits any solution, and therefore the correct answer is still 6.