Tag Archives: Recreational mathematics

Surfaces


Surfaces**
In the picture below you find 6 matchsticks. If we assume a matchstick is 1 inch long, the enclosed surfce has a size of 2.

triangle surfaces 2016-01-26 exercise as square

Now rearrange the 6 matches into two figures of 6 matchsticks each, in such a way that the surface of one figure is exactly 1.5 time the surface of the other figure.

You can check your solutions here

A new puzzle is published every Friday. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to three stars.

Playing with numbers – quickies


The next two problems are variants of easy problems from the Dutch 2008 Mathematics Olympiad.
1) 2016*
What is the smallest integer number that, when multiplying its digits, gives 2016?

2) Odd numbers *
Multiply all numbers between 1913 and 2012 (including 1913 and 2012). What is the last digit of the product?

You can check your solutions at 16 and 26 respectively.