Data & Statistics · Hard problem

A two-way table classifies $140$ students by grade ($9$th or $10$th) and by club membership (yes or no). There are $80$ ninth graders and $60$ tenth graders. In total, $54$ students belong to the club. The number of ninth graders in the club is $10$ more than the number of tenth graders in the club. How many tenth graders do NOT belong to the club?