From the given $3$ state counter made from $T$ flipflops, the next input sequence are as follows:
- $T_P=R$
- $T_Q=\overline{P}$
- $T_R=\overline{Q}$
| Initial State |
Current input |
Next State |
| $P$ |
$Q$ |
$R$ |
$T_P$ |
$T_Q$ |
$T_R$ |
$P^+$ |
$Q^+$ |
$R^+$ |
| 0 |
0 |
0 |
0 |
1 |
1 |
0 |
1 |
1 |
| 0 |
1 |
1 |
1 |
1 |
0 |
1 |
0 |
1 |
| 1 |
0 |
1 |
1 |
0 |
1 |
0 |
0 |
0 |
$%\begin{array} {|c|c|c|c|c|c|c|c|c|} \hline \text{Initial State} & & & \text{Current input} & & & \text{Next State} \\\hline P & Q & R & T_{P} & T_{Q} & T_{R} & P^{+} & Q^{+} & R^{+} \\\hline 0 & 0 & 0 & 0 & 1 & 1 & 0 & 1 & 1 \\\hline 0 & 1 & 1 & 1 & 1 & 0 & 1 & 0 & 1 \\\hline 1 & 0 & 1 & 1 & 0 & 1 & 0 & 0 & 0 \\\hline \end{array}$
In $T$ flip flop for low input$(0),$ the next state is $Q_n$ (current state) and for high input$(1),$ it toggles/complements the present state$(\overline{Q_n})$
$011,101,000$
Option A is correct.
