Problem: the amounts of time that three secretaries worked on a special project are in the ratio of 1 to 2 to 5 . if they worked a combined total of 128 hours , how many hours did the secretary who worked the longest spend on the project ?
Rationale: "8 x = 128 = > x = 16 therefore the secretary who worked the longest spent 16 x 5 = 90 hours on the project option ( a )"
annotated_formula: multiply(divide(128, add(add(1, 2), 5)), 5)