Convert the circuit below to the one using only NAND gates.

$(-2)$

A $8-$bit ALU is built up of $81-$bit ALU's, each one having an add time of $25$ ns $.$ If there is an additional $2_{?}$ nsec delay for propagation from one ALU to the next, how long does it take for the result of a $8-$Bit add to appear.

$14,00$p $000$pere

$200ns+14sec$

Draw a $4-$ Bit adder $($Block Level$)$ using $1-$ Bit

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