A person crosses a 1080 m long street in 14 minutes. What is his speed in km per hour?  Choose the correct choice from the following choices:
A) 4.1 B) 4.5 C) 4.6 D) 5.4 E) 5.5

Rationale: "speed = 1080 / ( 12 x 60 ) m / sec = 1.3 m / sec . converting m / sec to km / hr = 1.3 x ( 18 / 5 ) km / hr = 4.6 km / hr . answer : c"
Answer: C