You may also like

problem icon

Days and Dates

Investigate how you can work out what day of the week your birthday will be on next year, and the year after...

problem icon

Diophantine N-tuples

Can you explain why a sequence of operations always gives you perfect squares?

problem icon

DOTS Division

Take any pair of two digit numbers x=ab and y=cd where, without loss of generality, ab > cd . Form two 4 digit numbers r=abcd and s=cdab and calculate: {r^2 - s^2} /{x^2 - y^2}.