A and B walk around a circular track. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. If they start at 8 a.m. from the same point in opposite directions, how many times shall they cross each other before 11 a.m.?	Select:  A) 5  B) 6  C) 7  D) 8  E) 15
Relative speed = Speed of A + Speed of B (? they walk in opposite directions)   = 2 + 3= 
<gadget id="calculator">2 + 3</gadget>
<output>5</output>
5 rounds per hour=&gt; They cross each other 5 times in 1 hour   Time duration from 8 am to 11 am = 3 hours   Hence they cross each other 15 times before 11 am   Answer is 15
<result>E</result>
A and B walk around a circular track. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. If they start at 8 a.m. from the same point in opposite directions, how many times shall they cross each other before 11 a.m.?