Answer: (C) 14
Explanation: X’s position = 5th from the left: Y’s position = 6th from the right
After interchanging, X’s new position = Y’s former position = 13th from the left
Hence, Total number of boys = (13 + 6 – 1) = 18
Y’s new position = X’s old position = 5th from the left = (18 -5 + 1) = 14