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?
Select the correct option:
A) 10 hr	B) 12 hr	C) 15 hr	D) 18 hr	E) 17 hr
speed = 5.5-5= 
<gadget id="calculator">5.5-5</gadget>
<output>0.5</output>
0.5 kmph   dist= 8.5 km   time = dist/speed = 8.5/0.5= 
<gadget id="calculator">8.5/0.5</gadget>
<output>17</output>
17 hr   ANSW17 hrR 17 hr
<result>E</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?