07 September 2021

28 August 2021

658. Mathematical: 0 minus 3 is not 7

Easy Medium Hard Extreme


ADD 3 matchsticks to make the equation true.

The following rules apply:
- No number is greater than 9
- Negative numbers are not allowed
- You may not change the equal (=) sign

03 August 2021

657. Change the 2:3:4 ratio to 2:2:5

Easy Medium Hard Extreme


The above square is divided into 3 parts in the ratio 2:3:4. Change this ratio to 2:2:5 by moving only 1 matchstick.

29 July 2021

656. Three right angles

Easy Medium Hard Extreme


Three matchsticks form 2 right angles as shown in Figure A above. By moving only 1 matchstick you can create 3 right angles as shown in Figure B. However, this is only one solution and there are 7 more where 3 right angles can be created. Can you find them all?

The rules are:
- Start each time with the layout as in Figure A.
- Move only 1 matchstick.
- You may not move the horizontal matchstick in Figure A.

27 July 2021

655. Four to six squares

Easy Medium Hard Extreme


Move only 2 matchsticks to create 6 squares. The squares are allowed to differ in size.

However, squares must be linked and each matchstick must form the side of at least one square.

Show Answer

Don't miss the 2X2 square.

Hide Answer

10 July 2021

654. Increase the inner triangles

Easy Medium Hard Extreme


This puzzle is similar to but different from numbers 517 and 592.

In the figure above 9 matchsticks were placed on a triangular grid to form 7 inner triangles.

What is the maximum number of inner triangles you can create by rearranging the 9 matchsticks on the grid?

06 July 2021

653. The farmer and his 4 sons

Easy Medium Hard Extreme


A farmer lives on the area marked "A" on his farm. He decides to divide the rest of the farm between his 4 sons with the SIZE and SHAPE of each of the 4 farms exactly the same.

Add as many matchsticks as you want to the layout to show how he has done this.

04 July 2021

652. Three square units extreme

Easy Medium Hard Extreme


Credit: The Moscow puzzles (1972) Boris A. Kordemsky

The length of a matchstick is 1 unit, so in the layout above 12 matchsticks were used to create an area "W" of 3 square units. (see puzzle 121 and also how area W was calculated below)

There is another way to create 3 square units, but you may NOT MOVE the matchsticks which from line AC. Can you find it?

Take note of the calculations below as you might need some of the information in your solution.

The area W was calculated as:
= Total area ABC - area X - area Y - area Z
= 1/2(3 X 4) - 1 - 1 - 1
= 3 square units

Angle 𝛳 was calculated as:
= arcsine(AB/AC)
= arcsine(3/5)
= 36.869898 degrees

Show Answer

We must now proof that the area of the parallelogram is 3 square units.

To calculate the height:
sin𝛳 = height/1
height = sin(36.869898)
height = 0.6 unit

The area of the parallelogram is:
= base X height
= 5 X 0.6
= 3 square units

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03 July 2021

651. Three square units

Easy Medium Hard Extreme


The length of a matchstick is 1 unit. Use 12 matchsticks to create an area of 3 square units. To make your life easier, 8 of the 12 matches have already been placed in the correct positions.

Show Answer

Area A is exactly 3 square units. (4 - 1)

Hide Answer

19 June 2021

650. Three squares different in size

Easy Medium Hard Extreme


There are 5 squares in the layout above, 4 small and 1 big.

Move 2 matchsticks to create 3 squares of 3 different sizes.

16 June 2021

649. Three-way bridge

Easy Medium Hard Extreme


There are three islands in the ocean and your challenge is to construct a bridge to connect them. Unfortunately, as can be seen with matchsticks A, B and C, the length of a matchstick is just too short to connect the islands directly.

How would you construct an interlocking bridge, that can actually carry some weight in real life, by only using matchsticks A, B and C? Also, the three matchsticks are not allowed to touch the ocean.

08 June 2021

648. Divide into 2 parts

Easy Medium Hard Extreme


MOVE 2 matchsticks in the layout above to divide it into 2 parts equal in shape and size.

04 June 2021

647. Rugby

Easy Medium Hard Extreme


A rugby player missed a kick to goal by kicking the ball to the right of the posts and also lower than the crossbar.

MOVE only 2 matchsticks to make the ball go through the posts and over the crossbar. You may not move the ball.

Show Answer

Tilt your head to the right to see the solution.

Hide Answer

03 June 2021

646. Cross to squares

Easy Medium Hard Extreme


There are no squares in the layout above. Move 4 matchsticks to change the cross into 4 EQUAL squares.

02 June 2021

645. Fix the equation

Easy Medium Hard Extreme


You would need math skills to solve this one.

The equation 7/9 = 3 is not true. Move only 2 matchsticks to make it true.

01 June 2021

644. Polygon with 7 sides

Easy Medium Hard Extreme


Shown above is an eight sided convex polygon built from 2 squares and 6 triangles. 17 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 7 sides
2. 12 matchsticks to be used
3. All outside angles to be greater than 180 degrees
4. There must be 3 equal sized triangles
5. There must be 2 equal sized squares
6. All matchsticks must be flat on the surface.

30 May 2021

643. Cup and saucer

Easy Medium Hard Extreme


Move 4 matchsticks to convert the cup and saucer into 3 DIFFERENT in size triangles.

29 May 2021

642. Stacked triangles

Easy Medium Hard Extreme


In the figure above are 4 equal triangles. Move 4 matchsticks to create 2 equal triangles.

28 May 2021

641. Three different squares

Easy Medium Hard Extreme


MOVE 3 matchsticks to create only 3 squares. The 3 squares must have 3 DIFFERENT sizes.

Show Answer

Note that all matchsticks form part of a square i.e. there are no redundant matchsticks. There are also other solutions.

Hide Answer

24 May 2021

640. Big and small squares

Easy Medium Hard Extreme


There are 4 squares in the layout above. A broken matchstick is exactly half the length of a full length matchstick. Also, matchstick A is placed exactly in the middle of matchstick B.

Move 3 matchsticks to create 8 squares. All matchsticks don't have to be flat on the surface and square sizes may differ.

Show Answer

There are 5 small and 3 bigger squares.

Hide Answer

22 May 2021

639. From three to two squares

Easy Medium Hard Extreme


Reduce the number of squares from 3 to 2 by moving 3 matchsticks. Squares may differ in size.

21 May 2021

638. Create 5 triangles

Easy Medium Hard Extreme


Move 4 matchsticks to create 5 triangles. The triangles may differ in size.

Show Answer

There are 4 small triangles and one big triangle.

Hide Answer

18 May 2021

637. The sand timer

Easy Medium Hard Extreme


Credit: The Puzzles of Nobuyuki Yoshigahara.

In the layout above is a sand timer consisting of two equilateral triangles. Move 4 matchsticks to turn the sand timer upside down.

15 May 2021

636. Move two to create two squares

Easy Medium Hard Extreme


Another easy one, but can you solve it within 10 seconds?

Move 2 matchsticks to create 2 equal squares.

14 May 2021

635. Two is not equal to six

Easy Medium Hard Extreme


Two is not equal to six, but move only ONE matchstick to make the equation true. You may not change the equal (=) sign.

Show Answer

Solution 1: One is equal to the square root of one.
Solution 2: Eleven is equal to Roman numeral eleven.

Hide Answer