Equations and Formulae - Stage 4

In 15 years' time my age will be the square of my age 15 years ago. Can you work out my age, and when I had other special birthdays?

Five equations and five unknowns. Is there an easy way to find the unknown values?

A mother wants to share a sum of money by giving each of her children in turn a lump sum plus a fraction of the remainder. How can she do this in order to share the money out equally?

Take a triangular number, multiply it by 8 and add 1. What is special about your answer? Can you prove it?

All CD Heaven stores were given the same number of a popular CD to sell for £24. In their two week sale each store reduces the price of the CD by 25% ... How many CDs did the store sell at each price?

Given an equilateral triangle inside an isosceles triangle, can you find a relationship between the angles?

Polygons drawn on square dotty paper have dots on their perimeter (p) and often internal (i) ones as well. Find a relationship between p, i and the area of the polygons.

How have "Warmsnug" arrived at the prices shown on their windows? Which window has been given an incorrect price?

There is a particular value of x, and a value of y to go with it, which make all five expressions equal in value, can you find that x, y pair ?

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?

Which is bigger, n+10 or 2n+3? Can you find a good method of answering similar questions?

The heptathlon is an athletics competition consisting of 7 events. Can you make sense of the scoring system in order to advise a heptathlete on the best way to reach her target?

How Old Am I? Poster

Which is bigger?

What do you get when you raise a quadratic to the power of a quadratic?