problem Favourite Which is cheaper? Age 14 to 16 Challenge level When I park my car in Mathstown, there are two car parks to choose from. Can you help me to decide which one to use?
problem Favourite Quadratic harmony Age 16 to 18 Challenge level Find all positive integers a and b for which the two equations: x^2-ax+b = 0 and x^2-bx+a = 0 both have positive integer solutions.
problem Favourite Discrete trends Age 16 to 18 Challenge level Find the maximum value of n to the power 1/n and prove that it is a maximum.
problem Favourite Which is bigger? Age 14 to 16 Challenge level Which is bigger, n+10 or 2n+3? Can you find a good method of answering similar questions?
problem Favourite Squareness Age 16 to 18 Challenge level The family of graphs of x^n + y^n =1 (for even n) includes the circle. Why do the graphs look more and more square as n increases?
problem Favourite Tet-trouble Age 14 to 16 Challenge level Is it possible to have a tetrahedron whose six edges have lengths 10, 20, 30, 40, 50 and 60 units?
problem Favourite Giants Age 16 to 18 Challenge level Which is the bigger, 9^10 or 10^9 ? Which is the bigger, 99^100 or 100^99 ?
problem Favourite Unit interval Age 14 to 18 Challenge level Take any two numbers between 0 and 1. Prove that the sum of the numbers is always less than one plus their product?
problem Favourite Random inequalities Age 16 to 18 Challenge level Can you build a distribution with the maximum theoretical spread?
problem Favourite Approximating pi Age 14 to 18 Challenge level By inscribing a circle in a square and then a square in a circle find an approximation to pi. By using a hexagon, can you improve on the approximation?