Sausages come in packets of 12. Bread rolls come in packets of 18. Dan wants to buy enough packs of sausages and rolls so that there are an equal number of sausages and rolls. What is the minimum number of sausages and rolls he needs to buy?

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?