In a row of students, Ravi is 21st from either end of the row. How many students are there in a row?
In a row of students facing North, Rana is 10th to the left of Pallav, who is 21st from the right end. If Mohit, who is 17th from the left end, is 4thto the right of Rana, how many students are there in the row?