1.java

code problem 2: -1
class GenericEngine {public String engType = "GE-001";}
class CombustionEngine extends GenericEngine {public String engType = "CE-002";}
class JetEngine extends CombustionEngine {public String engType = "JE-003";}
 
public class Car {
    public void setEngine(Object o) {System.out.println("I have unknown engine");}
    public void setEngine(GenericEngine ge) {System.out.printf("I have generic engine: %s", ge.engType);}
    public void setEngine(CombustionEngine ce) {System.out.printf("I have combustion engine: %s", ce.engType);}
    public static void main(String[] args) {JetEngine e = new JetEngine(); new Car().setEngine(e);}
}