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 9.00 a.m. ?	Choose the correct option.
A) 7
B) 6
C) 5
D) 2
E) 8
C   5   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 5 times before 9.00 a.m.
<result>C</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 9.00 a.m. ?