58 Arithmetic & Algebraic Problems- THE REJECfED GUN
Here is a little military puzzle that may not give you a moment's difficulty.
It is such a simple question that a child can understand it and no knowledge
of artillery is required. Yet some of my readers may find themselves perplexed
for quite five minutes.
An inventor offered a new large gun to the committee appointed by our
government for the consideration of such things. He declared that when once
loaded it would fire sixty shots at the rate of a shot a minute. The War Office
put it to the test and found that it fired sixty shots an hour, but declined it,
"as it did not fulfill the promised condition."
"Absurd," said the inventor, "for you have shown that it clearly does all
that we undertook it should do."
"Nothing of the sort," said the experts. "It has failed."
Can you explain this extraordinary mystery? Was the inventor, or were the
experts, righ t?- TWENTY QUESTIONS
I am reminded of an interesting old game I used to playas a bachelor.
Somebody thinks of an object-say Big Ben, or the knocker on the front door,
or the gong of the clock in the next room, or the top button of his friend's
coat, or Mr. Baldwin's pipe. You have then to discover the object, by putting
not more than twenty questions, each of which must be answered by "yes" or
"no." You have to word your questions discreetly, because if you ask, for ex-
ample, "Is it animal, vegetable, or mineral?" you might get the unsatisfactory
answer "Yes," and so waste a question. We found that the expert rarely failed
to get an exact solution, and I have known some most remarkably difficult
cases solved by the twenty questions.
A novel limitation of the game is suggested to me, which will call for some
ingenuity, and the puzzle will doubtless be attacked in various ways by differ-
ent persons. It is simply this. I think of a number containing six figures. Can
you discover what it is by putting to me twenty questions, each of which can
only be answered by "yes" or "no"? After the twentieth question you must
give the number.