Label this plum tree graph to make it totally magic!
Find all the ways of placing the numbers 1 to 9 on a W shape, with
3 numbers on each leg, so that each set of 3 numbers has the same
A 2-Digit number is squared. When this 2-digit number is reversed
and squared, the difference between the squares is also a square.
What is the 2-digit number?
all, pick the number of times a week that you would like to eat
chocolate (try for more than once but less than 10 times as more
than this is simply greedy).
Multiply this number by 2 (just to be bold).
Add 5 (for Sunday).
Multiply it by 50.
If you have already had your birthday this year add 1760.
If you haven't had your birthday yet this year add 1759.
Now subtract the four digit year that you were born.
You should have a three digit number.
The first digit of this was your original number.
The next two numbers are your age.
This problem was first published in 2010. How does this work?
Does this work for any year? If not, can you adapt it so that it
Thanks to Jose Luis for the idea for this question.