A Person X started at 3 hours earlier at 40km/h from a place P, then another person Y followed him at 60km/h. Started his journey at 3 O'clock, afternoon. What is the diference in time when X was30 km ahead of Y and when Y was 30 km ahead of X?
Pick one:	A) 8h	B) 3h	C) 6h	D) 3h	E) 1h
Explanation:   Time ( when X was 30 km ahead of Y) = (120-30)/20= 
<gadget id="calculator">(120-30)/20</gadget>
<output>9/2 = around 4.5</output>
4.5h   Time ( when Y was 30 km ahead of X)= (120+30)/20= 
<gadget id="calculator">(120+30)/20</gadget>
<output>15/2 = around 7.5</output>
7.5 h   Thus, required difference in time= 3h   Answer: 3h
<result>B</result>
A Person X started at 3 hours earlier at 40km/h from a place P, then another person Y followed him at 60km/h. Started his journey at 3 O'clock, afternoon. What is the diference in time when X was30 km ahead of Y and when Y was 30 km ahead of X?