P is a point on the circumference of a circle radius r which rolls,
without slipping, inside a circle of radius 2r. What is the locus
The coke machine in college takes 50 pence pieces. It also takes a certain foreign coin of traditional design...
What happens to the perimeter of triangle ABC as the two smaller
circles change size and roll around inside the bigger circle?
Can all letters of the alphabet be represented using only a 5 by 5 array of cubes ?
Is it possible to create every combination of three letters in a 'perforated cube' ?
What difference does the orientation of the letters make ?
How many ways are there to orientate three non-symmetric letters such as F, J and P ?
What difference will it make to use letters that have symmetry of some kind ?