A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour?
Choose the correct choice from the following choices.
A) 3.6 B) 7.2 C) 8.4 D) 10 E) 8

Rationale: "speed = 600 / ( 5 x 60 ) m / sec . = 2 m / sec . converting m / sec to km / hr = ( 2 x ( 18 / 5 ) ) km / hr = 7.2 km / hr . answer : b"
Answer: B