Problem: of 30 applicants for a job , 16 had at least 4 years ' experience , 21 had degrees , and 5 had less than 4 years ' experience and did not have a degree . how many of the applicants had at least 4 years ' experience and a degree ?
Rationale: "set a : people with more than 4 years exp set b : people with degree aub = total - ( less than 4 exp and no degree ) aub = 30 - 5 = 25 aub = a + b - aib aib = 21 + 16 - 25 = 12 answer a"
annotated_formula: add(subtract(add(16, 21), subtract(30, 5)), subtract(21, 16))