We prove a conjecture of Yood regarding the nonexistence of submultipl
icative norms on the algebra C(T) of all continuous functions on a top
ological space T which admits an unbounded continuous function. We als
o exhibit a quotient of C(T) which does not admit a nonzero positive l
inear functional. Finally, it is shown that the algebra L(X) of all li
near operators on an infinite-dimensional vector space X admits no non
zero submultiplicative seminorm.