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.

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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.

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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

23 December 2017

571. Change the 2:3:4 ratio to 1:1:1

Easy Medium Hard Extreme


The above square is divided into 3 parts in the ratio 2:3:4. The ratio must be changed to 1:1:1 by moving only 1 matchstick.

Show Answer

The ratio 3:3:3 is equal to 1:1:1.

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16 December 2017

570. The biggest number

Easy Medium Hard Extreme


ADD 3 matchsticks to form the BIGGEST possible number. Your solution should only have THREE digits.

09 December 2017

569. Divide into 4 areas

Easy Medium Hard Extreme


Add 10 matchsticks inside the layout above to create 4 areas equal in SIZE and SHAPE.

02 December 2017

568. Change to numerical equation

Easy Medium Hard Extreme


The above equation is not true. Move 2 matchsticks to change it to a valid numerical equation.

25 November 2017

567. The wood log problem

Easy Medium Hard Extreme


In a factory are 5 machines with each machine producing 5 pieces of compressed wood logs. The weight of each wood log is 500 grams.

However, one of the 5 machines is faulty and produces 5 logs with weight slightly more than 500 grams for each log. You do not know which machine is faulty and also not by how much.

Available in the factory is a digital single-tray scale. (not a two-tray balance scale) You are allowed to weigh as many logs as you wish at a time, but may use the scale only twice. How can you find the faulty machine?

Show Answer

STEP 1:
Place one log from each machine on the scale and weigh. Let's assume your answer is 2 510 grams. You now know the faulty machine produces 10 grams more for each log. (2 510 grams - 2 500 grams) But you still don't know which machine is faulty...

STEP 2:
Place the logs on the scale as shown above. The total weight is supposed to be 7 500 grams. (15 logs X 500 grams) Let's assume your answer is 7 530 grams which means there are 30 grams more than expected. (7 530 grams - 7 500 grams) Your faulty machine would therefore be machine 3. (30 grams / 10 grams) If machine 1 was faulty the weight would have been 7 510 grams, machine 2 would be 7 520 grams etc.

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18 November 2017

566. Matchstick Grid: Diagonal heads

Easy Medium Hard Extreme


This puzzle is similar to but different from number 500.

If you count the matchstick heads in each diagonal, vertical and horizontal row you will get to the numbers as shown above.

Your challenge is to rearrange the matchsticks to have:
- 4 heads in each row
- 4 heads in each column
- 8 heads in each diagonal row.

Your solution must still be a 2X2 matchstick grid.

12 November 2017

565. Move 2 to form 2 triangles

Easy Medium Hard Extreme


Easy, but people seem to struggle with this one...

Move 2 matchsticks to form only 2 triangles.

Show Answer

Nobody said the 2 triangles must be equal in size!

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11 November 2017

564. Triangle 3X3: Remove 6

Easy Medium Hard Extreme


TAKE AWAY 6 matchsticks to leave you with 6 triangles. All triangles must be equal in size.

05 November 2017

29 October 2017

562. Mathematical: 5 minus 1 is not 1

Easy Medium Hard Extreme


ADD 2 matchsticks to the layout above to make the equation true. Can you find both solutions?

28 October 2017

561. Pathway with 7 matchsticks revisited

Easy Medium Hard Extreme


This puzzle is similar to but different from Number 492.

7 matchsticks are used to form a pathway as shown above. The challenge is to start at a point, move in the direction of the matchstick heads and visit each of the 7 matchsticks only once.

A solution is not possible in the existing figure above, but by changing the direction of only 2 matchsticks it can be achieved. How would you do this?

Show Answer

Change the directions of matchsticks 1 and 5. The pathway is then from matchstick 1 to 7.

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22 October 2017

560. Find the next number

Easy Medium Hard Extreme


Think out of the box to solve this one!

FIND THE NEXT NUMBER... PLEASE

Show Answer

The number of letters in the different words of the question represent the numbers.

FIND = 4
THE = 3
NEXT = 4
NUMBER = 6
PLEASE = 6

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21 October 2017

559. Divide into 4 areas

Easy Medium Hard Extreme


Add 11 matchsticks inside the layout above to create 4 areas equal in size.

15 October 2017

558. Move 1 and still have 5 squares

Easy Medium Hard Extreme


There are 5 equal squares in the figure above. Move 1 matchstick so you still have 5 equal squares.