In a garden, there are 10 rows and 12 columns of trees. The distance between any two trees is 2 m and a distance of lm is left from all sides of the boundary of the garden. What is the length of the garden?

Here,

The row is only accountable, as length is to be determined.

Now, the formula is= (n-1)*(Distance between two trees)

                                   = (10 - 1) * 2

                                   = 9*2

                                   = 18 m

And, additional 1 m is added on both side, thus (1 + 1) m is to be added with the resultant.

Thus, entire length of the garden is = 18 + (1 + 1)