Problem: one copy machine can make 30 copies a minute , and a second copy machine makes 20 copies a minute . if the two copiers work together , how long would it take them to make 2,000 copies ?
Rationale: "total work done by both machines in a minute = 30 + 20 = 50 copies total number of copies required = 2000 time = 2000 / 50 = 40 mins answer b"
annotated_formula: divide(power(20, const_3), add(30, 20))