24.
Each of P, Q, R, S, T, U and V has an exam on a different day of a week starting from Monday and ending on Sunday of the same week. T has an exam on Wednesday. Exactly 4 people have exams between S and R, neither of whom has an exam on Monday. Q has an exam immediately before and V has an exam immediately after P. U has an exam immediately before S. Who has an exam on Sunday?