numWordsOfLength.java

public int numWordsOfLength( int len ) {
    int cnt = 0;
    for (Object w: myList) {
        String s = (String)w; 
        if (s.length() == len) {
            cnt++;
        }
    }
    return cnt; 
    
}

removeWordsOfLength.java

public void removeWordsOfLength( int len ) {
    for (int i=myList.size() - 1; i>=0; i--) {
        String s = (String)myList.get(i);
        if (s.length() == len) {
            myList.remove(i); 
        }
    }
}