A person crosses a 800 m long street in 6 minutes. What is his speed in km per hour?  Choose the correct choice from the following options:
A) 5.2 km/hr.
B) 8.0 km/hr.
C) 7.2 km/hr.
D) 3.2 km/hr.
E) 4.2 km/hr.
B   8.0 km/hr.   Speed=(800/6 * 60) m/sec   = 2.2 m/sec.   Converting m/sec to km/hr   =(2.2*18/5) km/hr   = 8.0 km/hr.   Answer is 8.0 km/hr.
<result>B</result>
A person crosses a 800 m long street in 6 minutes. What is his speed in km per hour?