If pqr = 1 , rqt = 0 , and tpr = 0, which of the following must be zero?	Choose the most appropriate option
A) P B) Q C) R D) S E) T
pqr = 1 which means neither p / q/ r is 0   rq x t = 0 , we know r and q are not 0 from above hence t must be 0.   similarly p and r are not 0   t x p x r = 0, p and r are not 0 hence t =0.   option T
<result>E</result>
If pqr = 1 , rqt = 0 , and tpr = 0, which of the following must be zero?