Refer : https://gateoverflow.in/8250/gate2015-2-48
Here i dont understood how they calculated 12ns . I got that the first full adder will take 4.8ns time at that 4.8 ns we'll get the carry as well as the sum, in that duration the first XOR Ai xor Bi will be done for subsequent operands but for final sum the carry first need to be propagated through all full adder first
Why 4.8 + 3*2.4 ??