Consider a Boolean function $$f(w, x, y, z).$$ Suppose that exactly one of its inputs is allowed to change at a time. If the function happens to be true for two input vectors $${i_1} = < {w_1},{x_1},{y_1},{z_1} > $$ and $${i_2} = < {w_2},{x_2},{y_2},{z_2} > ,$$ we would like the function to remain true as the input changes from $${i_1}$$ to $${i_2}$$ ($${i_1}$$ and $${i_2}$$ differ in exactly one bit position), without becoming false momentarily. Let $$f\left( {w,x,y,z} \right) = \sum {\left( {5,7,11,12,13,15} \right)} .$$ Which of the following cube covers of $$f$$ will entire that the required property is satisfied?

Consider the circuit above. Which one of the following options correctly represents $$f(x,y,z)?$$

You are given a free running clock with a duty cycle of $$50$$% and a digital waveform $$f$$ which changes only at the negative edge of the clock. Which one of the following circuits (using clocked $$D$$ flip-flops) will delay the phase of $$f$$ by $${180^0}?$$

Consider the circuit in the diagram. The $$ \oplus $$ operator represents $$EX$$-$$OR.$$ The $$D$$ flip-flops are initialized to zeros (cleared).

The following data: $$100110000$$ is supplied to the ''data'' terminal in nine clock cycles. After that the values of $${q_2}{q_1}{q_0}$$ are