a person crosses a 1080 m long street in 12 minutes . what is his speed in km per hour ?
"speed = 1080 / ( 12 x 60 ) m / sec = 1.5 m / sec . converting m / sec to km / hr = 1.5 x ( 18 / 5 ) km / hr = 5.4 km / hr . answer : d"
divide(divide(1080, const_1000), divide(multiply(12, const_60), const_3600))