In a row of trees , if a tree is 7^th from the left side and 14^th to the right side. Then how many trees are there in the line?

A. 18

B. 19

C. 20

D. 21

The number of Trees in a Row

The total trees a row contains
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
If we count the above row, we will come to know that

7 is the position of the left side

And 7 is also a position of 14th from the right side, thus there will 20