Quiz “DANGO
3 Brothers”
Shinji Kinoshita, MD
Human
Welfare Studies 3: 93-105, 2000

The
above figure shows 9 DANGOs (Japanese dumplings) and 8 KUSHIs (straight
skewers). On each skewer, there are 3 (brothers of) dumplings.
Remove 2 out of the 9 dumplings to other positions and skewer
these dumplings so as to increase the number of skewers from 8 to
10. On each skewer, there should be 3 dumplings, and there should
not be 2 or 4 dumplings. There will be three forms of answers in
this quiz, which are shown in the addendum
at the end of this book.
The original form of this quiz was created by Sir
Isaac Newton (1642-1727) as follows: (from: Henry E. Duedeney:
Amusements in mathematics).
“Plant
nine trees so that they shall form ten straight rows with three
trees in every row.”