Students are sitting in a row in which the position of X is 17th from the left and that of Y is 14th from the right. If they interchange their positions, X's position becomes 7th from the left. How many students are there in the row?
If the first 10 terms and the last 10 terms of the given expression are interchanged in such a way that the first term is interchanged with the last, the second with the second last, the third with the third last and soon, what will the fifth term from the right be in the new arrangement?