Question 1
Andy and Ben go on an 8 km trip using one bicycle shared between them. For each of them, their walking speed is 4 km per hour and their cycling speed is 16 km per hour. They both start at the same point and leave at the same time towards the same destination, where Andy rides the bicycle, while Ben walks. At a certain point, Andy dismounts and leaves the bicycle behind, and then walks to the destination. When Ben reaches the bicycle, he mounts it immediately and rides it for the rest of the trip. Knowing that Ben and Andy arrive at the destination at the exact same time, how many minutes does the whole trip take for each of them?