Position of Sham from the left in a row of students is 12, whereas the position of Rajni sitting in the same row is 12th from the right. After interchanging their positions, the position of the Sham becomes 16th from the left. What is the total number of students in the row?
Sum of positions of an item from top(right) and bottom(left) of a list is always equal to the sum of the positions of the first and last items. So total items is = 12 + 16 - 1 = 27.