11 August 2018

596. M for Matchstick

Easy Medium Hard Extreme


Add 2 matchsticks to form 10 triangles. The matchsticks may overlap and do not have to be flat on the surface.

Show Answer

There are 4 Small triangles:

ALK
BCM
OME
LOJ

There are 6 combined triangles

AJH
BDE
LEF
MJF
KOH
CDO

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28 July 2018

595. Polygon with 8 sides

Easy Medium Hard Extreme


Shown above is a seven sided convex polygon built from 2 squares and 3 triangles. 12 matchsticks were used to achieve this. The outside angles are all greater than 180 degrees as illustrated with angle "a" above.

Create your own convex polygon. The following rules apply:

1. Polygon must have 8 sides
2. 17 matchsticks to be used
3. All outside angles to be greater than 180 degrees
4. There must be 6 equal sized triangles
5. There must be 2 equal sized squares
6. All matchsticks must be flat on the surface.

14 July 2018

594. Mathematical: 8 minus 3 is not 3

Easy Medium Hard Extreme


MOVE only 1 matchstick to make the equation true. Can you find the 3 solutions?

07 July 2018

593. Divide into 3 shapes

Easy Medium Hard Extreme


Add 4 matchsticks to divide the triangle into 3 equal parts. The 3 parts may differ in shape but must be equal in size.

Show Answer

If the length of 1 matchstick is 1 unit, the size of the big triangle (A + B + C + D) is:
= 1/2 X 4 X 3
= 6 square units

The size of rectangle A is:
= 2 X 1
= 2 square units

The size of triangle B is:
= 1/2 X 1 X 2
= 1 square unit
But C = B based on the same calculation which results in B + C = 2 square units.

Size of part D is:
= Big triangle - size A - size B - size C
= 6 - 2 - 1 - 1
= 2 square units

It should be clear that A = D = (B + C)

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01 July 2018

592. Increase the inner triangles

Easy Medium Hard Extreme


This puzzle is similar to but different from No 517.

In the figure above 8 matchsticks were placed on a grid to form 6 inner triangles.

What is the maximum number of inner triangles you can create by rearranging the 8 matchsticks?

09 June 2018

590. Balance the scale: Move 1

Easy Medium Hard Extreme


The vertical matchsticks on the scale all have the same weight. To balance the unbalanced scale you need to MOVE 1 matchstick. Where would you place it?

Show Answer

In the original puzzle:

Left of balancing point: (3x1) + (1x1) + (1x1) + (1x1) = 6 units
Right of balancing point: (3x1) + (4x1) = 7 units

From the above we can see we need to move a matchstick right of the balancing point. This is done by placing the matchstick as shown in the solution.

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02 June 2018

589. Missing number

Easy Medium Hard Extreme


This puzzle is extremely difficult because you would have to think out of the box to solve it!

Replace the "?" with the missing number in the sequence.

Show Answer

First you need to turn the figure by an angle of 180 degrees. Then replace the "?" with "87" to form a sequence 86, 87, 88 and 89.

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26 May 2018

588. Route Map: Change one direction

Easy Medium Hard Extreme


13 matchsticks are used to form a pathway as shown above. The challenge is to start at point A, move in the direction of the matchstick heads, visit each of the 13 matchsticks only once and finish at point B.

A solution is not possible in the existing figure above, but by changing the direction of only 1 matchstick it can be achieved. How would you do this?

Show Answer

Change the direction of matchstick 10. The pathway is then from matchstick 1 to 13.

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12 May 2018

586. Little square and rectangle

Easy Medium Hard Extreme


Four matchsticks form a little square as shown above. Your challenge is to create a rectangle with size EXACTLY 3 times the size of the little square.

Note the following:
1. All matchstick heads have been removed.
2. The 4 matchsticks are exactly the same. (thickness, length etc)
3. Only the 4 matchsticks above may be used in your solution.
4. Not all matchsticks have to be used in your solution.
5. You are allowed to break one matchstick.

05 May 2018

585. Four-sided figures

Easy Medium Hard Extreme


A four-sided figure (square or rectangle) can be stand-alone or combined. How many four-sided figures do you count with at least one broken matchstick in them?

Show Answer

There are 14 four-sided figures in total

Stand-alone: C, D, G
Two combined: B+C, D+E, D+F, F+G, G+H
Three combined: A+B+C, F+G+H, E+G+H
Five combined: A+B+C+D+E, D+E+F+G+H
Eight combined: A+B+C+D+E+F+G+H

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29 April 2018

584. The four rectangles

Easy Medium Hard Extreme


There are 3 rectangles of size 2X1 in the layout above. They are ABDC, EGLJ and FHMK.

Move 3 matchsticks to create FOUR equal rectangles each of size 2X1.

Show Answer

The four 2X1 rectangles are ABDC, FHMK, CDON and GPQL

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21 April 2018

583. Divide the square

Easy Medium Hard Extreme


Divide the square into 3 parts by adding 8 matchsticks. The 3 parts must be equal in size but not necessarily in shape.

14 April 2018

582. Mathematical: 4 plus 5 is not 5

Easy Medium Hard Extreme


MOVE 3 matchsticks to make the equation true. Consider yourself brilliant if you can find the 3 solutions.

07 April 2018

581. Remove 6 leaving 3 squares

Easy Medium Hard Extreme


Take away 6 matchsticks to leave you with 3 equal squares. The 3 squares may not touch.

30 March 2018

580. Divide the rectangle in ratio 3:4:5

Easy Medium Hard Extreme


Divide the rectangle into 3 areas with ratio 3:4:5 by placing 7 matchsticks inside the layout.

Show Answer

There are also other solutions.

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25 March 2018

17 March 2018

03 March 2018

577. One square

Easy Medium Hard Extreme


Place the 8 matchsticks in such a way that it forms a square. The 4 broken matchsticks have the same length but are not half the length of the full matchstick.

17 February 2018

576. Divide into 4 areas

Easy Medium Hard Extreme


Add 15 matchsticks inside the layout above to create 4 areas equal in SIZE.

11 February 2018

575. Three matchstick node notations

Easy Medium Hard Extreme


Figures A and B above are two examples illustrating how "nodes" and "node notations" are formed by using 3 matchsticks. There are 7 more "node notations" using only 3 matchsticks. Can you find them all?

The rules are:
1. Matchstick heads can be ignored
2. All matchsticks must be flat on the surface
3. Each matchstick must touch at least one other matchstick

04 February 2018

574. Triangle 3X3: Remove 4 leaving 6 triangles

Easy Medium Hard Extreme


Take away 4 matchsticks to leave only 6 triangles. The triangles must be equal in size.

Show Answer

There are also other solutions.

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28 January 2018

573. The third grader puzzle

Easy Medium Hard Extreme


This puzzle was given to third graders in a school somewhere in the world...

ADD only 1 matchstick to make the equation true.

13 January 2018