A SR flip-flop and a T flip-flop

An SR flip-lfop and a D flip-flop

A T flip-flop and a D flip-flop

Two D flip-flops

External clock is to be provided

It is more complex

Both (a) and (b)

Generally they involve stability problem

Comparator circuit

Demultiplexer

Frequency to voltage converter

Voltage to frequency converter

2

5

6

8

clock input of all flip-flops

clock input of one flip-flops

J and K inputs of all flip-flops

J and K inputs of one flip-flop