8. Design a circuit for a full adder using only NOR gates. A full adder has three inputs (A, B, Cin) and two outputs (Sum and Cout). The expressions are: Sum=ABCinCout=(AB)+(Cin(AB)) The circuit should have exactly 4 NOR gates. 9. Convert the binary number 101110 to decimal. 10. What is a FF? 11. How many FFs is needed to build a 32 bit Johnoson counter? 12. How many fFs is needed to build a 32 bit Ring counter? 13. What is the difference between a Johnson counter and Ring counter