Question 20
Marc cycles at a constant speed and walks at a constant speed. A round trip from home to school takes 20 minutes entirely by bike, or 60 minutes entirely on foot. Yesterday he cycled towards school, left his bike at Eva’s house on the way, then walked to school. Returning, he walked to Eva’s house, collected his bike and cycled home. His total travel time was 52 minutes. What fraction of the whole journey was by bike?