Informational Site NetworkInformational Site Network
Privacy
 
Home Top Rated Puzzles Most Viewed Puzzles All Puzzle Questions Random Puzzle Question Search


THE FOUR SEVENS.

(Money Puzzles)
In the illustration Professor Rackbrane is seen demonstrating one of the
little posers with which he is accustomed to entertain his class. He
believes that by taking his pupils off the beaten tracks he is the
better able to secure their attention, and to induce original and
ingenious methods of thought. He has, it will be seen, just shown how
four 5's may be written with simple arithmetical signs so as to
represent 100. Every juvenile reader will see at a glance that his
example is quite correct. Now, what he wants you to do is this: Arrange
four 7's (neither more nor less) with arithmetical signs so that they
shall represent 100. If he had said we were to use four 9's we might at
once have written 99+9/9, but the four 7's call for rather more
ingenuity. Can you discover the little trick?


Answer:

The way to write four sevens with simple arithmetical signs so that they
represent 100 is as follows:--
7 7
-- x -- = 100.
.7 .7
Of course the fraction, 7 over decimal 7, equals 7 divided by 7/10,
which is the same as 70 divided by 7, or 10. Then 10 multiplied by 10 is
100, and there you are! It will be seen that this solution applies
equally to any number whatever that you may substitute for 7.










Random Questions

Catching The Hogs
MISCELLANEOUS PUZZLES
Two New Magic Squares.
Magic Squares Problem.
Card Magic Squares.
Magic Squares Problem.
A Puzzle For Motorists.
Unicursal and Route Problems
A Family Party.
Money Puzzles
A Wonderful Village.
Unclassified Problems.
A Reversible Magic Square
MISCELLANEOUS PUZZLES
The Perplexed Plumber
MISCELLANEOUS PUZZLES
The Cardboard Box.
Patchwork Puzzles
The Industrious Bookworm.
Unclassified Problems.
The Squire's Puzzle
CANTERBURY PUZZLES
The City Luncheons.
Combination and Group Problems
Setting The Board.
The Guarded Chessboard
Exercise For Prisoners.
The Guarded Chessboard
The Board In Compartments.
The Guarded Chessboard