56. Up the Hill. Willie-Lazybones climbed up the hill at a speed of $1 \frac{1}{2}$ km/h, and descended at a speed of $4 \frac{1}{2}$ km/h, so the entire journey took him exactly 6 hours. How many kilometers is it from the base to the top of the hill?
56. To the top of the hill is \(6 \frac{3}{4}\) km. Upwards, Willy-Lazybones climbed for \(4 \frac{1}{2}\) hours, and downwards he descended in \(1 \frac{1}{2}\) hours.