A book of mathematical and reasoning problems
Subtitle: fifty brain twisters.
Publisher: Van Nostrand
Published: 1962
Place of publication: Princeton, N.J
Language: eng
Number of pages: 109
Subjects: Mathematical recreations.
Other titles: The Observer, London.; Fifty brain twisters.
Notes: London ed. (Faber) has title: Fifty Observer brain-twisters; a book of mathematical and reasoning problems.
"The problems ... have all appeared at one time or another in the Observer."