The number of comparators in 4-bit flash ADC is

For the 4 bit DAC shown in Figure, the output voltage $${V_0}$$ is

A sequential circuit using D flip-flop and logic gates is shown in the figure, where X and Y are the inputs and Z is the output. The circuit is

For the logic circuit shown in Figure, the required input condition (A, B, C) to make the output (X)=1.