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Consider a carry lookahead adder for adding two n-bit integers, built using gates of fan-in at most two. The time to perform addition using this adder is

1. Θ(1)
2. Θ(log(n))
3. Θ(√n)
4. Θ(n)

Correct answer: Θ(log(n))

Solution

The carry lookahead adder improves the speed of addition by calculating carry signals in parallel, allowing the addition process to be completed in logarithmic time relative to the number of bits, as it reduces the depth of the circuit to a logarithmic scale.

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