In a row of students in a class, Ravi is 17th from either end of the row. How many students are there in the class?

A certain number of students are standing in a row. Rishabh stands 40th from the left. Mahak stands 42nd from the right. Mahak is standing to the right of Rishabh. If there are only 5 students between Rishabh and Mahak, how many students are standing in the row?

Mahesh ranked 21st from the top and 15th from the bottom in his class. How many students are there in the class?