Sam displays cans in 3 triangular stacks. With the same number he could make one large triangular stack or stack them all in a square based pyramid. How many cans are there how were they arranged?
Here is a collection of puzzles about Sam's shop sent in by club members. Perhaps you can make up more puzzles, find formulas or find general methods.
Triangle numbers can be represented by a triangular array of squares. What do you notice about the sum of identical triangle numbers?
I have forgotten the number of the combination of the lock on my briefcase. I did have a method for remembering it... It went as follows:
The number is equal to the sum of the cubes of its own digits.
It is a three digit number less than 500
It is the sum of consecutive factorials.
It is a triangle number.