1.  Choose the set of figures which follows the given rule. Rule: Closed figures losing their sides and open figures gaining their sides. 


2.  Choose the set of figures which follows the given rule. Rule: Any figure can be traced by a single unbroken line without retracting. 


3.  Choose the set of figures which follows the given rule. Rule: Closed figures gradually become open and open figures gradually become closed. 


4.  Choose the set of figures which follows the given rule. Rule: Closed figures become more and more open and open figures become more and more closed. 


5.  Choose the set of figures which follows the given rule. Rule: The series becomes complex as it proceeds. 

