Problem: a person crosses a 500 m long street in 4 minutes . what is his speed in km per hour ?
Rationale: "distance = 500 meter time = 4 minutes = 4 x 60 seconds = 240 seconds speed = distance / time = 500 / 240 = 2.08 m / s = 2.08 ã — 18 / 5 km / hr = 7.5 km / hr answer : a"
annotated_formula: divide(divide(500, const_1000), divide(multiply(4, const_60), const_3600))