Problem: if two - third of a bucket is filled in 6 minute then the time taken to fill the bucket completely will be .
Rationale: "2 / 3 filled in 6 mint 1 / 3 filled in 3 mint thn 2 / 3 + 1 / 3 = 6 + 3 = 9 minutes answer : d"
annotated_formula: multiply(divide(6, const_2), const_3)