In a row of students facing north, Aarav is 12th from the left end and Meenakshi is 18th from the right end. They interchange places, and Aarav becomes 25th from the left end. How many students are in the row?

Explanation

1. 01

   After the swap Aarav stands where Meenakshi stood.

2. 02

   That place is 25th from the left (Aarav's new position) and 18th from the right (Meenakshi's old position).

3. 03

   Total $= 25 + 18 - 1 = 42$.