Two boys starts from the same place walking at the rate of 5 kmph and 5.5 kmph respectively in the same direction. What time will they take to be 8.5 km apart?  Choices
A) 17hr  B) 14hr  C) 12hr  D) 19hr  E) 20hr
Explanation:   relative speed =5.5−5=0.5 kmph (because they walk in the same direction)   distance =8.5 km   time=distance/speed=8.5/0.5= 
<gadget id="calculator">8.5/0.5</gadget>
<output>17</output>
17 hr   17hrNSWER IS 17hr
<result>A</result>
Two boys starts from the same place walking at the rate of 5 kmph and 5.5 kmph respectively in the same direction. What time will they take to be 8.5 km apart?