Question Two (25 marks) a) Use 74LS138 and a NAND gate to implement the following function; [5marks] f(A, B, C) ABC-AB b) Convert the two's complement number, (0101011.01)zs to the following; Binary [6marks] i)Decimal ) Hexadecimal c) For the timing diagram shown in Figure 2, find the simplest switching expression for f(A, B, C) and draw its circuit diagram [5marks] 6