How many D flip-flops are needed to represent 23 different states?

Given: An 8:1 multiplexer has data inputs D0, D1, …, D7, select inputs S2:0, and output Y. Suppose D0 = 1, D1 = 0, D2 = 0, D3 = 0, D4 = 1, D5 = 0, D6 = 1, D7 = 1, S2 = 0, S1 = 0, and S0 = 1.  What is the value of Y?

A timing diagram is given for inputs to a basic D Flip-Flop. What is the value of the Q output of the D Flip-Flop at time = 5 ns? Assume the delay from inputs changing to output changing is negligible.

Given: If you were to put this function into the K-map below, what value would go into the square marked S24?

How many D flip-flops are needed to represent 6 different states?

A truth table with four output functions is given. Function Y1 will be implemented using a 4:16 decoder that has address inputs A3:0 and outputs Y0, Y1, …, Y15.  Which outputs need to be connected to an OR gate to produce function Y1 (do not confuse function Y1 with output Y1 on the decoder)? 

Given: F(A,B,C).  Which of the following is the minterm of F that corresponds to A=0, B=1, C=0?

A timing diagram is given for inputs to a D Flip-Flop with Enable (active high). What is the value of the Q output of the D Flip-Flop with Enable at time = 11 ns? Assume the delay from inputs changing to output changing is negligible.

How many D flip-flops are needed to represent 11 different states?

Given the following circuit: What function is implemented by Y2?