Three cars entered the parking lot at the same time, and the attendant isn't quite sure about whose car is which. However, he knows that:
a. Cuthbert drove the BMW if and only if Mr. Cooper drove the Audi.
b. Albert drove the Cadillac if and only if Mr. Cooper drove the BMW.
c. Cuthbert is Mr. Brown if and only if Mr. Andrews drove the BMW.
d. Bert is Mr. Andrews if and only if Cuthbert drove the BMW.
e. Mr. Cooper drove the Audi if and only if Albert is Mr. Brown.
f. Cuthbert is Mr. Brown if and only if Albert drove the Cadillac.
Who arrived in which car?
Suppose Cuthbert is Mr. Brown. Applying (c) and (f), we would have
Albert Cooper driving the Cadillac, Bert Andrews driving the BMW, and
Cuthbert Brown driving the Audi, but that goes against (a), so Cuthbert
is not Mr Brown, Mr Andrews didn't drive the BMW, and Albert didn't
drive the Cadillac.
From (b) Mr. Cooper didn't drive the BMW either, so Mr. Brown did.
Albert must have driven the Audi (only possibility) and Cuthbert the
Cadillac. From (a), Albert isn't Cooper, so he's Andrews, and the
Albert Andrews Audi
Bert Brown, BMW
Cuthbert Cooper, Cadillac