A car crosses a 720 m long bridge in 2 minutes. What is the speed of car in km per hour?	Select
A) 20.5 km/hr
B) 21.6 km/hr
C) 31.6 km/hr
D) 15.6 km/hr
E) 22.3 km/hr
Speed = 720	m/sec.   360/60m/s   = 6 m/sec.   Converting m/sec to km/hr (see important formulas section)   =6 x	18/5 km/hr   5   = 21.6 km/hr   21.6 km/hr
<result>B</result>
A car crosses a 720 m long bridge in 2 minutes. What is the speed of car in km per hour?