308 Answerssquare root of 5. In the second case the sine is I divided by the square root
of 12 + 22 , which is I divided by the square root of 5. Thus the first is exactly
double the second.
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A H- THE SIX SUBMARINES
It will be seen from the illustration
that this puzzle is absurdly easy-
when you know how to do it! And yet
I have not the slightest doubt that
many readers found it a hard nut to
crack. It will be seen that every match
undoubtedly touches every other
match.
[The number of matches can be
increased to seven and still meet the
puzzle's conditions. See my Scientific
American Book of Mathematical Puz-
zles & Diversions (Simon & Schuster,
1959), p. lI5.-M. G.]- ECONOMY IN STRING
The total length of string that passes along the length, breadth, or depth
must in every case be the same to allow of the maximum dimensions-that is,
4 feet. When the reader is told this, or has found it for himself (and I think
the point will be found interesting), the rest is exceedingly easy. For the string