Screen Recording 2021 02 22 at 751 05 PM Suppose a list A contains: 30 students in MATH List B contains 35 students in ENGLISH -there are 20 names on BOTH find # of students: Only on lista A has 30 names, and 20 are on list B IN COMMON,hence 30-20 names only on list A A = INCLUDE, BOTH LISTS = discard (subtract) Only on List B N(A) = 30. N(B) =35 N(B) - 0fA n B) = 35-20 - 15 On list A or list B N(a) + n(b) - (A n B)) 30. +. 35.- 20 45 ?????????????????? Your supply ALL KIDS in MATH 101. And ALL KIDS in ENGLISH 101 M-100. E=100 Totals 200?????? Inclusion-exclusion Rule If INCLUIDE then COUNT IF NOT, then DO NOT COUNT (subtract?) If two lists, then count distinct elements, And DISCOUNT COMMON elements