The document contains 8 questions from an exam (ITA 2012). Question 1 asks to determine the number of students (n) given information about the percentages of students studying different subjects and the number studying certain subject combinations totaling 63 students. There is no solution. Question 2 asks if a given function f(x) is bijective and if so, to find the inverse function f^-1(x). Question 3 asks to determine the value of n and the sum of elements in the first column of the inverse matrix A^-1, given information about the determinant of a matrix A.