A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 11.00 a.m. ?
Answers
A) 15	B) 12	C) 10	D) 12	E) 8
A   15   Relative speed = 2 + 3= 
<gadget id="calculator">2 + 3</gadget>
<output>5</output>
5 rounds per hour.   So, they cross each other 5 times in an hour and 2 times in half an hour.   Hence, they cross each other 15 times before 11.00 a.m.
<result>A</result>
A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 11.00 a.m. ?