Let’s start with a problem:

“A ladder hangs over the side of a ship anchored in port. The bottom rung of the ladder touches the water. The ladder is 30 cm wide and 270 cm long. The rungs are 1 cm thick and the distance between them is 34 cm. If the tide is rising at a rate of 15cm per hour, how long will it be before the water reaches the top rung?”