The choir consists of 5 boys and 6 girls. In how many ways can the singers be arranged in a row, so that all the boys are together? Do not differentiate between arrangements that are obtained by swapping two boys or two girls.
A valid argument is often defined as one in which it is not possible for all the premises to be true and the conclusion false. A circular argument is sometimes defined as one in which one of the premises is identical to the conclusion. From these definitions we can infer that...
(A) Every circular argument is valid as long as its premises are true.
(B) Every valid argument is circular.
(C) No circular argument is valid.
(D) Some circular arguments are valid, and some are not.
(E) Some circular arguments are not valid, and some valid arguments are not circular.