Ratio and proportion

Ever wondered what it would be like to vaporise a diamond? Find out inside...

Which is a better fit, a square peg in a round hole or a round peg in a square hole?

Points P, Q, R and S each divide the sides AB, BC, CD and DA respectively in the ratio of 2 : 1. Join the points. What is the area of the parallelogram PQRS in relation to the original rectangle?

A square is divided into four rectangles and a square. Can you work out the ratio of the side lengths of the rectangles?

Weekly Problem 37 - 2007
This regular hexagon has been divided into four trapezia and one hexagon.... what is the ratio of the lengths of sides p, q and r?

A brief introduction to PCR and restriction mapping, with relevant calculations...

How long will it take Mary and Nigel to wash an elephant if they work together?

Can you work out the fraction of the original triangle that is covered by the green triangle?