A person crosses a 1800 m long street in 12 minutes. What is his speed in km per hour?
Choose the correct choice from the following
A) 4.1 B) 4.5 C) 4.8 D) 5.4 E) 9

Rationale: "speed = 1800 / ( 12 x 60 ) m / sec = 2.5 m / sec . converting m / sec to km / hr = 2.5 x ( 18 / 5 ) km / hr = 9 km / hr . answer : e"
Answer: E