Every student in the 6th grade at ps 500 must read exactly three of the principal's four favorite books. if 34 read math for fun, 36 read everyone loves math, 38 read cool math, and 12 read math is for me, how many students are in the 6th grade at ps 500? (a) 30 (b) 40 (c) 60 (d) 90 (e) 120