How can you, in the simplest way, divide it into four equal and similar parts by four straight cuts?
Can you draw twenty-two straight lines within this circle so that they divide it into four similar parts, each having three of the dots within its borders?
Each line must be at right angles to another.
Cut up this triangle into 5 parts,
Trianglewhich can be reassembled to form this triangle.
The peculiar series of numbers, as arranged in this triangular form, is said to have been perfected by Pascal.
| 1 | |||||||
| 2 | 1 | ||||||
| 3 | 3 | 1 | |||||
| 4 | 6 | 4 | 1 | ||||
| 5 | 10 | 10 | 5 | 1 | |||
| 6 | 15 | 20 | 15 | 6 | 1 | ||
| 7 | 21 | 35 | 35 | 21 | 7 | 1 | |
| 8 | 28 | 56 | 70 | 56 | 28 | 8 | 1 |
It has the property of showing, without calculation, how many selections or combinations can be made at a time out of a larger number. Thus to find how many selections of 3 at a time can be made out of 8 we look for the third number on the horizontal row that commences with 8, and find the answer 56.
The series is formed thus: Set down the numbers 1, 2, 3, etc., as far as you please, in a vertical row. To the right of 2 place 1, add them together, and set 3 under the 1. Then add 3 to 3, and set the result below, and so on, always placing the sum of two numbers that are side by side below the one on the right.
This diagram shows an ancient and curious method of multiplication, which will be novel to most of our readers.
In this instance 534 is multiplied by 342. Draw a square of nine cells with diagonals, fill the three top cells, as is shown, by multiplying the 5 by the 3, the 4 and the 2. Then multiply in similar way the 3 and the 4 by these same figures. Turn the square round so that the diagonals are upright, and add. Of course, placing the numbers thus is the same practically as carrying them by our ordinary rule.
In this diagram 27 counters are arranged in 9 rows, with 6 in each row.
Can you rearrange them so that with similar conditions they all fall within the borders of one equilateral triangle?
Can you discover a very familiar saying that is buried in these lines?
Place eight cards of two different colours alternately in one row, then with four moves bring all of one colour together.
| A ♠ |
2 ♡ |
3 ♣ |
4 ♢ |
5 ♣ |
6 ♢ |
7 ♣ |
8 ♡ |
Two cards (without altering their relative position) are to be moved at a time, and placed somewhere in the same line, one of them at least touching another card.
The missing words are spelt with the same five letters.
Cut out this diagram, and paste it on a card. Hand it to anyone, and ask him to fix upon whichever number he pleases, and merely to tell you in which columns this appears.
| I. | II. | III. | IV. | |||||||||||||||
| 1 | 33 | 65 | 97 | 2 | 34 | 66 | 98 | 4 | 36 | 68 | 100 | 8 | 40 | 72 | 104 | |||
| 3 | 35 | 67 | 99 | 3 | 35 | 67 | 99 | 5 | 37 | 69 | 101 | 9 | 41 | 73 | 105 | |||
| 5 | 37 | 69 | 101 | 6 | 38 | 70 | 102 | 6 | 38 | 70 | 102 | 10 | 42 | 74 | 106 | |||
| 7 | 39 | 71 | 103 | 7 | 39 | 71 | 103 | 7 | 39 | 71 | 103 | 11 | 43 | 75 | 107 | |||
| 9 | 41 | 73 | 105 | 10 | 42 | 74 | 106 | 12 | 44 | 76 | 108 | 12 | 44 | 76 | 108 | |||
| 11 | 43 | 75 | 107 | 11 | 43 | 75 | 107 | 13 | 45 | 77 | 109 | 13 | 45 | 77 | 109 | |||
| 13 | 45 | 77 | 109 | 14 | 46 | 78 | 110 | 14 | 46 | 78 | 110 | 14 | 46 | 78 | 110 | |||
| 15 | 47 | 79 | 111 | 15 | 47 | 79 | 111 | 15 | 47 | 79 | 111 | 15 | 47 | 79 | 111 | |||
| 17 | 49 | 81 | 113 | 18 | 50 | 82 | 114 | 20 | 52 | 84 | 116 | 24 | 56 | 88 | 120 | |||
| 19 | 51 | 83 | 115 | 19 | 51 | 83 | 115 | 21 | 53 | 85 | 117 | 25 | 57 | 89 | 121 | |||
| 21 | 53 | 85 | 117 | 22 | 54 | 86 | 118 | 22 | 54 | 86 | 118 | 26 | 58 | 90 | 122 | |||
| 23 | 55 | 87 | 119 | 23 | 55 | 87 | 119 | 23 | 55 | 87 | 119 | 27 | 59 | 91 | 123 | |||
| 25 | 57 | 89 | 121 | 26 | 58 | 90 | 122 | 28 | 60 | 92 | 124 | 28 | 60 | 92 | 124 | |||
| 27 | 59 | 91 | 123 | 27 | 59 | 91 | 123 | 29 | 61 | 93 | 125 | 29 | 61 | 93 | 125 | |||
| 29 | 61 | 93 | 125 | 30 | 62 | 94 | 126 | 30 | 62 | 94 | 126 | 30 | 62 | 94 | 126 | |||
| 31 | 63 | 95 | 127 | 31 | 63 | 95 | 127 | 31 | 63 | 95 | 127 | 31 | 63 | 95 | 127 | |||
| V. | VI. | VII. | |||||||||||
| 16 | 48 | 80 | 112 | 32 | 48 | 96 | 112 | 64 | 80 | 96 | 112 | ||
| 17 | 49 | 81 | 113 | 33 | 49 | 97 | 113 | 65 | 81 | 97 | 113 | ||
| 18 | 50 | 82 | 114 | 34 | 50 | 98 | 114 | 66 | 82 | 98 | 114 | ||
| 19 | 51 | 83 | 115 | 35 | 51 | 99 | 115 | 67 | 83 | 99 | 115 | ||
| 20 | 52 | 84 | 116 | 36 | 52 | 100 | 116 | 68 | 84 | 100 | 116 | ||
| 21 | 53 | 85 | 117 | 37 | 53 | 101 | 117 | 69 | 85 | 101 | 117 | ||
| 22 | 54 | 86 | 118 | 38 | 54 | 102 | 118 | 70 | 86 | 102 | 118 | ||
| 23 | 55 | 87 | 119 | 39 | 55 | 103 | 119 | 71 | 87 | 103 | 119 | ||
| 24 | 56 | 88 | 120 | 40 | 56 | 104 | 120 | 72 | 88 | 104 | 120 | ||
| 25 | 57 | 89 | 121 | 41 | 57 | 105 | 121 | 73 | 89 | 105 | 121 | ||
| 26 | 58 | 90 | 122 | 42 | 58 | 106 | 122 | 74 | 90 | 106 | 122 | ||
| 27 | 59 | 91 | 123 | 43 | 59 | 107 | 123 | 75 | 91 | 107 | 123 | ||
| 28 | 60 | 92 | 124 | 44 | 60 | 108 | 124 | 76 | 92 | 108 | 124 | ||
| 29 | 61 | 93 | 125 | 45 | 61 | 109 | 125 | 77 | 93 | 109 | 125 | ||
| 30 | 62 | 94 | 126 | 46 | 62 | 110 | 126 | 78 | 94 | 110 | 126 | ||
| 31 | 63 | 95 | 127 | 47 | 63 | 111 | 127 | 79 | 95 | 111 | 127 | ||
You can then in a moment, and at a glance, pick out the number that is chosen.
Let us suppose that these black dots represent a succession of pillar boxes. It will be seen that a postman, starting from the circle, and going along the dotted lines, turns round 18 corners.
Can he take a course which involves fewer turnings?
Here is an ingenious paper and scissors puzzle:—
Divide a square card into three pieces, so that these can be reunited to form No. 2 or No. 3 of this diagram.
(From an old Sanscrit source, quoted by Longfellow in his “Kavanagh.”)
Ten times the square root of a flock of geese, seeing the clouds collect, flew to the Manus lake. One-eighth of the whole flew from the edge of the water among a tangle of water lilies, and three couples were seen playing in the water. Tell me, my young girl with beautiful locks, what was the whole number of geese?
| ♚ | |||||||
| ♖ | ♘ | ♖ |
Leaving the Black King in his position, place the three white men so that he stands checkmated.
An American paper published the following:—
Next day this parody appeared in a rival paper:—
Can you fill in the missing words?
If we look with one eye only, or with eyes half-closed, at these groups of circular dots, they assume the appearance familiar to us in honeycomb. This is an effect of the contrast and opposition of the black and white in the sensation of the retina.
Although the black and the white circles are of the same diameter the irradiation is in their case so intense that the white circles appear to be larger than the black.
This excellent illusion appeared in a recent number of the “Strand Magazine”:—
Most persons will at first see the passages under these arches as running upwards from left to right, but presently, as their line of vision shifts, the arches will take a downward course from right to left. This very curious effect will well repay a little patience, if it is not realised at once.
I have 91 bananas on my barrow, of two qualities; some I sell at four a penny, and the better sort at three a penny. If I had sold them in mixed lots at seven for twopence, I should have made a penny more. How many were there of each quality?
The Puzzle Problem—
A passenger in a first-class railway carriage notices that the top of a factory window due S.W. of him coincides with a mark on the carriage window, and does not move from it while the train is running five and a half miles.
At the end of that distance the compass bearing of the chimney is due N.W. How far was the passenger from the chimney when he first noticed it?
is solved by 31⁄2 miles.
We give a diagram to make the points clear.
As the chimney top does not move from its place on the window, it is clear that the train is running on a segment of a circle having the chimney for its centre. It follows that the observer’s distance throughout is equal to the radius of that circle, and the radius of a circle of which the quadrant measures 51⁄2 miles is 31⁄2 miles within about 11 ft.
The cross had been taken out from the centre of this flag, and its owner, who had an ingenious turn of mind, found that by cutting what remained into two pieces, and rejoining them, he could make it into a perfect flag without any waste of material.
How did he accomplish this?
Add two more pieces similar in shape and size to that marked A, and one similar to B, C, and D respectively, and then readjust the eleven parts so that they form a perfect square.
The missing words are spelt with the same letters.
This is a simple arrangement of eight matches, by which two squares and four similar triangles are formed.
Three towns are buried in these lines.
A hospital was built in six detached blocks, and it was the duty of the night watchman to go completely round every block at fixed hours to see that all was safe.
What was his shortest course?
Can you rearrange the twelve counters on this board of 36 squares so that there are two counters on each row, column, and diagonal?
| ◎ | ◎ | ◎ | ◎ | ◎ | ◎ |
| ◎ | ◎ | ◎ | ◎ | ◎ | ◎ |
There must not be more than these two counters in the same straight line.