**Solution:**

To find Vipul's position from the right end, we need to know the total number of persons in the row. In this case, we are given that there are 12 persons in the row.

To determine Vipul's position from the right end, we can subtract his position from the total number of persons in the row and then add 1.

Let's calculate:

Total number of persons in the row = 12

Position of Vipul from the left end = 7

**Calculating Vipul's position from the right end:**

Step 1: Subtract Vipul's position from the total number of persons in the row
12 - 7 = 5

Step 2: Add 1 to the result obtained in step 1
5 + 1 = 6

Therefore, Vipul's position from the right end is 6th.

**Explanation:**

When we count positions from the left end, we start with 1 and keep increasing the count as we move to the right. Similarly, when we count positions from the right end, we start with 1 and keep increasing the count as we move to the left.

In this case, Vipul's position from the left end is 7th. So, there are 6 persons to his right. When we count positions from the right end, Vipul would be the 6th person.

This calculation is based on the fact that the total number of persons in the row remains the same regardless of the direction from which we count the positions. So, if there are 12 persons in the row, Vipul's position from the right end would be 6th.