A linked list is formed from the objects of class VotersList. The class structure is given below…

int countNodes(VotersList start)
{
    if (start == null)
        return 0;
    else
    {
        if (start.age >= 60)
            return 1 + countNodes(start.link);
        else
            return countNodes(start.link);
    }
}

Explanation: The method recursively traverses the linked list node by node using the link reference. At each node, if age is 60 or more it adds 1 to the count returned by the recursive call on the rest of the list (start.link); otherwise it simply returns the count from the rest of the list. The base case (start == null) returns 0 when the end of the list is reached. Tested with a 4-node list of ages {65, 45, 70, 30}, the method correctly returns 2 (the nodes with age 65 and 70).