Q1:

interface DoMath 
{
    double getArea(int rad); 
}
interface MathPlus 
{
    double getVol(int b, int h); 
}
/* Missing Statements ? */

which two code fragments inserted at end of the program, will allow to compile?

1. class AllMath extends DoMath { double getArea(int r); }
2. interface AllMath implements MathPlus { double getVol(int x, int y); }
3. interface AllMath extends DoMath { float getAvg(int h, int l); }
4. class AllMath implements MathPlus { double getArea(int rad); }
5. abstract class AllMath implements DoMath, MathPlus { public double getArea(int rad) { return rad * rad * 3.14; } }