What is the result of the Boolean expression PQ + PQR + PQRS + PQRST?
A
PQ
B
PQ + RS + T
C
P + Q + R + S + T
D
PQRST
Correct Option:
A
Explanation
PQ+PQR+PQRS+PQRST
Factor out PQ:
PQ(1+R+RS+RST).
Because 1+X=1 in Boolean algebra, the bracket becomes 1. Hence the whole expression simplifies to PQ. This is an application of the absorption principle.
