A yacht which is anchored in a port has a ladder hanging over the side.
It is low tide right now. The length of the ladder is 150cm, the distance between each rung is 30cm and the bottom rung touches the water.
The tide rises at a rate of 15cm an hour. When will the water reach the fifth rung?
Answer
The water will never reach the fifth rung as the tide will also raise the yacht.