One method of
solving puzzles like this involves setting up a
grid representing all
possible relations between the
variables in the problem, and filling it in with X's for
impossible relations or O's for
certain ones (or ?'s for
unknown relations in this example, though you'd ordinarily use
blank cells), and using it to assist in solving
by process of elimination.
The grid for this problem might look like this:
b f e
Smith ? ? ?
Jones ? ? ?
Robinson ? ? ?
Note that some other information, like the passengers, incomes, and homes are not included. These are merely window dressing, though this puzzle has more than most.
Full Solution
Return to Old Chestnuts.