Time and Distance

1. Speed, Time and Distance:

   Speed =		Distance		,	Time =		Distance		,	Distance = (Speed x Time).
   		Time					Speed

2. km/hr to m/sec conversion:

   x km/hr =		x x	5		m/sec.
   			18

3. m/sec to km/hr conversion:

   x m/sec =		x x	18		km/hr.
   			5

4. If the ratio of the speeds of A and B is a : b, then the ratio of the

   the times taken by then to cover the same distance is	1	:	1	or b : a.
   	a		b

5. Suppose a man covers a certain distance at x km/hr and an equal distance at y km/hr. Then,

   the average speed during the whole journey is		2xy		km/hr.
   		x + y

   Examples : 

      

1.	A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour?
	A. 3.6 B. 7.2 C. 8.4 D. 10 Answer: Option B Explanation: Speed = 600 m/sec. 5 x 60    = 2 m/sec.    = 2 x 18 km/hr 5    = 7.2 km/hr.