a person crosses a 1440 m long street in 12 minutes . what is his speed in km per hour ?
"speed = 1440 / ( 12 x 60 ) m / sec = 2 m / sec . converting m / sec to km / hr = 2 x ( 18 / 5 ) km / hr = 7.2 km / hr . answer : e"
divide(divide(1440, const_1000), divide(multiply(12, const_60), const_3600))