A person crosses a 1080 m long street in 12 minutes. What is his speed in km per hour?  Select the correct option.
A) 4.1  B) 4.5  C) 4.8  D) 5.4  E) 5.5

Rationale: "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"
Answer: D