If a man crosses a 400 m long street in 5 minutes. What is his speed?  Choices:  A) 7 km/hr  B) 7.1 km/hr  C) 7.2 km/hr  D) 4.8 km/hr  E) 8.5 km/hr
distance = 400 meter   time = 5 minutes = 5 x 60 seconds = 300 seconds   Speed = distance/time=400/300=1.33m/s=1.33×18/5 km/hr=4.8 km/hr   4.8 km/hr
<result>D</result>
If a man crosses a 400 m long street in 5 minutes. What is his speed?