The frequency of the clock signal applied to the rising edge triggered D flip-flop shown in figure is 10 kHz. The frequency of the signal available at Q is?

The answer I got is 3 but it’s given as 5 and in the solution they are mentioning that the no. of flip flops here are defined by the sequence not the no. of states??

Consider the circuit given below: MSB and LSB of mod 10 ripple counter act as clock to ripple down and up counter respectively. Initially all the counters were cleared and output of comparator was A=B. The clock pulse is applied. Find the minimum no of clock pulses required to make A=B again.

The following sequential circuit has initial state $QAQB = 00$ with one input $X$ and one output $Z.$ What is the minimum input sequence which takes the machine to state $11?$ $(A) 00$ $(B) 10$ $(C) 11$ $(D)$ State $11$ is not reachable