Let's calculate the total number of people in the row.

Initially, 'A' is in the 11th position from the left, and 'B' is in the 10th position from the right. After interchanging, 'A' becomes 18th from the left. This means 'B' must now occupy the 18th position from the left. Let the total number of people in the row be denoted by "N". Since 'B' is in the 10th position from the right, the total number of people in the row is: $N =$ position of 'B' from left $+$ position of 'B' from right $- 1$

From the given information, we know that after the interchange, 'A' becomes 18th from the left. This means the number of people in the row is: $N = 18 + 10 - 1$

Now, subtract the 2 persons (A and B) from the total count to find how many persons are there other than 'A' and 'B'.

Persons other than 'A' and 'B' $= N - 2$

The total number of persons in the row, other than 'A' and 'B', is 25.