Question

Explain the rule followed by the pattern which would give the number of coloured block in any grid on the pattern shown here?

Answer 1

In all the three grids shown here:

• Each row have two coloured blocks except the middle row.
• In every grid the middle row has only one coloured block.

So, we can say that the total number of coloured blocks in a grid is one less than twice the number of rows in each grid.

It means, Number of coloured blocks = 2 $\times$ Number of rows - 1

If we denote the number of rows by a variable 'a', then:
Number of coloured blocks = (2 $\times$ a) - 1 = 2a - 1