Q: A ship anchored in a port has a ladder which hangs over the side. The length of the ladder is 10 feet, the distance between each rung is 1 foot and the bottom rung touches the water. The tide rises 18 inches per hour. How long will it take for the water to reach the fifth rung from the top?
A: If the tide is rising, then the ship is also rising on the water. So water will still reach the bottom rung.
