Bhairvi is ranked 16th from the top and 5th from the bottom among the students who passed the annual examination. If the total number of failed students is 7, how many students appeared in the exam?
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 passed is = 16 + 5 - 1 = 20. Those appeared = failed + passed = 20 + 7 = 27.