Implement the functions $(,,)=+,$ and $(,,)=(+)$ using a$)$ One decoder of appropriate size and two OR gates b$)$ One decoder of appropriate size and the minimal number of two$-$input OR gates c$)$ One decoder of appropriate size and minimal number of NAND gates d$)$ Implement F$($a$,$b$,$c$)$ using one $4-$to$-1$ size multiplexer. Show your circuit $2)$ Implement a two$-$input NOR gate using appropriate size multiplexer only. Show your circuit