Read the details provided below carefully and answer the following question.

A certain number of persons sit in a row facing north. E is the only neighbor of Q. Five persons sit between E and T. K sits immediately to the right of T. B sits second to the right of K. Two persons sit between K and Y. The number of persons sitting between E and H is twice the number of persons sitting between B and Y. The number of persons sitting to the right of Y is four less than the number of persons sitting to the left of Y. More than twelve persons sit in the row.

How many persons sit in the row?

The correct answer is 19.

Step 1: Determine the positions of Q, E, T, K, and B.
All persons sit facing North.
"E is the only neighbor of Q": This means Q must sit at an extreme end of the row.
Case 1: Place Q at the extreme left end (Position 1). Since E is Q's only neighbor, E sits at Position 2.
"Five persons sit between E and T": Counting 5 positions to the right of E (positions 3, 4, 5, 6, 7), T sits at Position 8.
"K sits immediately to the right of T": K sits at Position 9.
"B sits second to the right of K": B sits at Position 11.

Step 2: Determine the position of Y.
"Two persons sit between K and Y": K is at Position 9. If Y were placed to the left of K (Position 6), the total number of persons in the row would be less than 12, violating the condition that more than twelve persons sit in the row. Thus, Y must sit to the right of K.
Placing 2 persons (Position 10 and Position 11/B) between K (Position 9) and Y places Y at Position 12.

Step 3: Determine the position of H.
The number of persons sitting between B (Position 11) and Y (Position 12) is 0.
"The number of persons sitting between E and H is twice the number of persons sitting between B and Y":
Number of persons between E and H = 2 × 0 = 0.
Therefore, H sits immediately next to E. Since Position 1 is occupied by Q and Position 2 by E, H must sit at Position 3.

Step 4: Calculate the total number of persons in the row.
Y is at Position 12, which means there are 11 persons sitting to the left of Y.
"The number of persons sitting to the right of Y is four less than the number of persons sitting to the left of Y":
Number of persons to the right of Y = 11 - 4 = 7 persons.

$\text{Total persons}=11+1+7=19$

Since 19 is greater than 12, this seating arrangement satisfies all given constraints. Hence, there are 19 persons sitting in the row.