Answer
a) S=0, T=1.
b) S=0, T=1.
c) S=0, T=0.
Work Step by Step
Use the half-adder table given in the book,
a) For P=1, Q=1, R=1, we have C1=1, S1=0, C2=0, thus S=0, T=1.
b) For P=0, Q=1, R=0, we have C1=0, S1=1, C2=0, thus S=0, T=1.
c) For P=1, Q=0, R=1, we have C1=0, S1=1, C2=1, thus S=0, T=0.
