Compare and contrast Ripple-Carry Adder and Carry-Look ahead Adder.

1. In a 4-bit ripple-carry adder assume that each full-adder is implemented (a) and each single logic gate (e.g., AND, OR, XOR, etc.) has a propagation delay of 10 ns. What is the earliest time this 4-bit ripple-carry adder can be sure of having a valid summation output? Explain how you reached your answer and how you did your calculations.

2. In a 16-bit ripple-carry adder what is the earliest time this 16-bit ripple-carry adder can be sure of having a valid summation output? Explain how you reached your answer and how you did your calculations.

3. In a 4-bit carry-look-ahead adder using a carry-look-ahead circuit assume the same gate delays as in (2). What is the earliest time this 4-bit carry-look-ahead adder can be sure of a valid summation output? Explain how you reached your answer and how you did your calculations