A three state switch has three outputs. These are

AB + AB = A(B + B) = A . 1 = A.

If A = 0, Y = 1 and A = 1, Y = 0 Therefore Y = A.

Minimum number of outputs when input is decimal 1 and maximum number of outputs when input is decimal 8.

Since V(1) is lower state than V(0) it is a negative logic circuit. Since diodes are in parallel, it is an OR gate.

7BF₁₆ = 7 x 16² + 11 x 16¹ + 15 x 16⁰ = 1983 in decimal = 0111 1011 1111 in binary.

or

Y = (A + B)C + DE.

4 = 2², in up scaling digit will be shifted by two bit in right direction.

Any number of inputs are possible.

The octal system has 8 digits 0 to 7.

A = 11100101. Therefore A = 00011010 and A' = A + 1 = 00011011 = 16 + 8 + 2 + 1 = 27. Therefore A = -27.